Styling multi-line conditions in if statements

Question

Sometimes I break long conditions in ifs onto several lines  The most obvious way to do this is     if  cond1     val1  and cond2     val2  and       cond3     val3  and cond4     val4          do something   Isn t very very appealing visually  because the action blends with the conditions  However  it is the natural way using correct Python indentation of 4 spaces   For the moment I m using     if      cond1     val1  and cond2     val2  and           cond3     val3  and cond4     val4          do something   But this isn t very pretty   -   Can you recommend an alternative way

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What if we only insert an additional blank line between the condition and the body and do the rest in the canonical way?

if (cond1 == 'val1' and cond2 == 'val2' and
    cond3 == 'val3' and cond4 == 'val4'):

    do_something

p.s. I always use tabs, not spaces; I cannot fine-tune...

User · Answer

This doesn t improve so much but     allCondsAreOK    cond1     val1  and cond2     val2  and                  cond3     val3  and cond4     val4    if allCondsAreOK     do something

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Here s my very personal take  long conditions are  in my view  a code smell that suggests refactoring into a boolean-returning function method  For example   def is action  required           return  cond1     val1  and cond2     val2              and cond3     val3  and cond4     val4     Now  if I found a way to make multi-line conditions look good  I would probably find myself content with having them and skip the refactoring   On the other hand  having them perturb my aesthetic sense acts as an incentive for refactoring   My conclusion  therefore  is that multiple line conditions should look ugly and this is an incentive to avoid them

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You don t need to use 4 spaces on your second conditional line   Maybe use   if  cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4        do something   Also  don t forget the whitespace is more flexible than you might think   if             cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4            do something if     cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4        do something   Both of those are fairly ugly though   Maybe lose the brackets  the Style Guide discourages this though    if cond1     val1  and cond2     val2  and      cond3     val3  and cond4     val4       do something   This at least gives you some differentiation   Or even   if cond1     val1  and cond2     val2  and                          cond3     val3  and                          cond4     val4       do something   I think I prefer   if cond1     val1  and      cond2     val2  and      cond3     val3  and      cond4     val4       do something   Here s the Style Guide  which  since 2010  recommends using brackets

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All respondents that also provide multi-conditionals for the if statement is just as ugly as the problem presented  You don t solve this problem by doing the same thing     Even the PEP 0008 answer is repulsive   Here is a far more readable approach  condition   random randint 0  100    to demonstrate anti conditions    42  67  12  if condition not in anti conditions      pass   Want me to eat my words  Convince me you need multi-conditionals and I ll literally print this and eat it for your amusement

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Here s what I do  remember that  all  and  any  accepts an iterable  so I just put a long condition in a list and let  all  do the work   condition    cond1     val1   cond2     val2   cond3     val3   cond4     val4    if all condition      do something

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Someone has to champion use of vertical whitespace here      if       cond1    val1      and cond2    val2      and cond3    val3           do stuff     This makes each condition clearly visible  It also allows cleaner expression of more complex conditions   if      cond1    val1      or                cond2 1    val2 1           and cond2 2  gt   val2 2           and cond2 3    bad2 3                     do more stuff     Yes  we re trading off a bit of vertical real estate for clarity  Well worth it IMO

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I ve been struggling to find a decent way to do this as well  so I just came up with an idea  not a silver bullet  since this is mainly a matter of taste    if bool condition1 and         condition2 and                     conditionN       foo       bar     I find a few merits in this solution compared to others I ve seen  namely  you get exactly an extra 4 spaces of indentation  bool   allowing all conditions to line up vertically  and the body of the if statement can be indented in a clear ish  way  This also keeps the benefits of short-circuit evaluation of boolean operators  but of course adds the overhead of a function call that basically does nothing  You could argue  validly  that any function returning its argument could be used here instead of bool  but like I said  it s just an idea and it s ultimately a matter of taste   Funny enough  as I was writing this and thinking about the  problem   I came up with yet another idea  which removes the overhead of a function call  Why not indicate that we re about to enter a complex condition by using extra pairs of parentheses  Say  2 more  to give a nice 2 space indent of the sub-conditions relative to the body of the if statement  Example   if    foo and       bar and       frob and       ninja bear         do stuff     I kind of like this because when you look at it  a bell immediatelly rings in your head saying  hey  there s a complex thing going on here    Yes  I know that parentheses don t help readability  but these conditions should appear rarely enough  and when they do show up  you are going to have to stop and read them carefuly anyway  because they re complex    Anyway  just two more proposals that I haven t seen here  Hope this helps someone

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I m surprised not to see my preferred solution   if  cond1     val1  and cond2     val2      and cond3     val3  and cond4     val4        do something   Since and is a keyword  it gets highlighted by my editor  and looks sufficiently different from the do something below it

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I prefer this style when I have a terribly large if-condition   if       expr1     and  expr2 or expr3      and hasattr thingy1     eq         or status   HappyTimes         do stuff   else      do other stuff

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Just a few other random ideas for completeness s sake   If they work for you  use them   Otherwise  you re probably better off trying something else   You could also do this with a dictionary    gt  gt  gt  x     cond1     val1    cond2     val2    gt  gt  gt  y     cond1     val1    cond2     val2    gt  gt  gt  x    y True   This option is more complicated  but you may also find it useful   class Klass object       def   init   self  some vars            initialize conditions here     def   nonzero   self           return  self cond1     val1  and self cond2     val2  and                 self cond3     val3  and self cond4     val4    foo   Klass   if foo      print  foo is true   else      print  foo is false     Dunno if that works for you  but it s another option to consider   Here s one more way   class Klass object       def   init   self            initialize conditions here     def   eq   self           return  self cond1     val1  and self cond2     val2  and                self cond3     val3  and self cond4     val4    x   Klass some values  y   Klass some other values  if x    y      print  x    y  else      print  x  y    The last two I haven t tested  but the concepts should be enough to get you going if that s what you want to go with    And for the record  if this is just a one time thing  you re probably just better off using the method you presented at first   If you re doing the comparison in lots of places  these methods may enhance readability enough to make you not feel so bad about the fact that they are kind of hacky

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I m surprised not to see my preferred solution   if  cond1     val1  and cond2     val2      and cond3     val3  and cond4     val4        do something   Since and is a keyword  it gets highlighted by my editor  and looks sufficiently different from the do something below it

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Personally  I like to add meaning to long if-statements  I would have to search through code to find an appropriate example  but here s the first example that comes to mind  let s say I happen to run into some quirky logic where I want to display a certain page depending on many variables   English   If the logged-in user is NOT an administrator teacher  but is just a regular teacher  and is not a student themselves      if not user isAdmin   and user isTeacher   and not user isStudent        doSomething     Sure this might look fine  but reading those if statements is a lot of work  How about we assign the logic to label that makes sense  The  label  is actually the variable name   displayTeacherPanel   not user isAdmin   and user isTeacher   and not user isStudent   if displayTeacherPanel      showTeacherPanel     This may seem silly  but you might have yet another condition where you ONLY want to display another item if  and only if  you re displaying the teacher panel OR if the user has access to that other specific panel by default   if displayTeacherPanel or user canSeeSpecialPanel        showSpecialPanel     Try writing the above condition without using variables to store and label your logic  and not only do you end up with a very messy  hard-to-read logical statement  but you also just repeated yourself  While there are reasonable exceptions  remember  Don t Repeat Yourself  DRY

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What if we only insert an additional blank line between the condition and the body and do the rest in the canonical way?

if (cond1 == 'val1' and cond2 == 'val2' and
    cond3 == 'val3' and cond4 == 'val4'):

    do_something

p.s. I always use tabs, not spaces; I cannot fine-tune...

User · Answer

I ve resorted to the following in the degenerate case where it s simply AND s or OR s   if all   cond1     val1   cond2     val2   cond3     val3   cond4     val4       if any   cond1     val1   cond2     val2   cond3     val3   cond4     val4        It shaves a few characters and makes it clear that there s no subtlety to the condition

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Adding to what  krawyoti said    Long conditions smell because they are difficult to read and difficult to understand  Using a function or a variable makes the code clearer  In Python  I prefer to use vertical space  enclose parenthesis  and place the logical operators at the beginning of each line so the expressions don t look like  floating    conditions met         cond1     val1       and cond2     val2       and cond3     val3       and cond4     val4        if conditions met      do something   If the conditions need to be evaluated more than once  as in a while loop  then using a local function is best

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I know this thread is old  but I have some Python 2 7 code and PyCharm  4 5  still complains about this case   if foo is not None      if  cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4                  some comment about do something             do something   Even with the PEP8 warning  visually indented line with same indent as next logical line   the actual code is completely OK   It s not  over-indenting       there are times I wish Python would ve bit the bullet and just gone with curly braces   I wonder how many bugs have been accidentally introduced over the years due to accidental mis-indentation

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Pack your conditions into a list  then do smth  like   if False not in Conditions      do something

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I suggest moving the and keyword to the second line and indenting all lines containing conditions with two spaces instead of four   if  cond1     val1  and cond2     val2    and cond3     val3  and cond4     val4        do something   This is exactly how I solve this problem in my code  Having a keyword as the first word in the line makes the condition a lot more readable  and reducing the number of spaces further distinguishes condition from action

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if cond1     val1  and        cond2     val2  and        cond3     val3  and        cond4     val4         do something   or if this is clearer     if cond1     val1        and cond2     val2        and cond3     val3        and cond4     val4         do something   There is no reason indent should be a multiple of 4 in this case  e g  see  Aligned with opening delimiter    http   google-styleguide googlecode com svn trunk pyguide html showone Indentation Indentation

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It seems worth quoting PEP 0008  Python s official style guide   since it comments upon this issue at modest length      When the conditional part of an if -statement is long enough to require that it be written across multiple lines  it s worth noting that the combination of a two character keyword  i e  if    plus a single space  plus an opening parenthesis creates a natural 4-space indent for the subsequent lines of the multiline conditional  This can produce a visual conflict with the indented suite of code nested inside the if -statement  which would also naturally be indented to 4 spaces  This PEP takes no explicit position on how  or whether  to further visually distinguish such conditional lines from the nested suite inside the if -statement  Acceptable options in this situation include  but are not limited to     No extra indentation  if  this is one thing and     that is another thing       do something      Add a comment  which will provide some distinction in editors   supporting syntax highlighting  if  this is one thing and     that is another thing         Since both conditions are true  we can frobnicate      do something      Add some extra indentation on the conditional continuation line  if  this is one thing         and that is another thing       do something      Note the  not limited to  in the quote above  besides the approaches suggested in the style guide  some of the ones suggested in other answers to this question are acceptable too

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Someone has to champion use of vertical whitespace here      if       cond1    val1      and cond2    val2      and cond3    val3           do stuff     This makes each condition clearly visible  It also allows cleaner expression of more complex conditions   if      cond1    val1      or                cond2 1    val2 1           and cond2 2  gt   val2 2           and cond2 3    bad2 3                     do more stuff     Yes  we re trading off a bit of vertical real estate for clarity  Well worth it IMO

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It seems worth quoting PEP 0008  Python s official style guide   since it comments upon this issue at modest length      When the conditional part of an if -statement is long enough to require that it be written across multiple lines  it s worth noting that the combination of a two character keyword  i e  if    plus a single space  plus an opening parenthesis creates a natural 4-space indent for the subsequent lines of the multiline conditional  This can produce a visual conflict with the indented suite of code nested inside the if -statement  which would also naturally be indented to 4 spaces  This PEP takes no explicit position on how  or whether  to further visually distinguish such conditional lines from the nested suite inside the if -statement  Acceptable options in this situation include  but are not limited to     No extra indentation  if  this is one thing and     that is another thing       do something      Add a comment  which will provide some distinction in editors   supporting syntax highlighting  if  this is one thing and     that is another thing         Since both conditions are true  we can frobnicate      do something      Add some extra indentation on the conditional continuation line  if  this is one thing         and that is another thing       do something      Note the  not limited to  in the quote above  besides the approaches suggested in the style guide  some of the ones suggested in other answers to this question are acceptable too

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Just a few other random ideas for completeness s sake   If they work for you  use them   Otherwise  you re probably better off trying something else   You could also do this with a dictionary    gt  gt  gt  x     cond1     val1    cond2     val2    gt  gt  gt  y     cond1     val1    cond2     val2    gt  gt  gt  x    y True   This option is more complicated  but you may also find it useful   class Klass object       def   init   self  some vars            initialize conditions here     def   nonzero   self           return  self cond1     val1  and self cond2     val2  and                 self cond3     val3  and self cond4     val4    foo   Klass   if foo      print  foo is true   else      print  foo is false     Dunno if that works for you  but it s another option to consider   Here s one more way   class Klass object       def   init   self            initialize conditions here     def   eq   self           return  self cond1     val1  and self cond2     val2  and                self cond3     val3  and self cond4     val4    x   Klass some values  y   Klass some other values  if x    y      print  x    y  else      print  x  y    The last two I haven t tested  but the concepts should be enough to get you going if that s what you want to go with    And for the record  if this is just a one time thing  you re probably just better off using the method you presented at first   If you re doing the comparison in lots of places  these methods may enhance readability enough to make you not feel so bad about the fact that they are kind of hacky

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Adding to what  krawyoti said    Long conditions smell because they are difficult to read and difficult to understand  Using a function or a variable makes the code clearer  In Python  I prefer to use vertical space  enclose parenthesis  and place the logical operators at the beginning of each line so the expressions don t look like  floating    conditions met         cond1     val1       and cond2     val2       and cond3     val3       and cond4     val4        if conditions met      do something   If the conditions need to be evaluated more than once  as in a while loop  then using a local function is best

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I suggest moving the and keyword to the second line and indenting all lines containing conditions with two spaces instead of four   if  cond1     val1  and cond2     val2    and cond3     val3  and cond4     val4        do something   This is exactly how I solve this problem in my code  Having a keyword as the first word in the line makes the condition a lot more readable  and reducing the number of spaces further distinguishes condition from action

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all  and  any  are nice for the many conditions of same type case  BUT they always evaluates all conditions  As shown in this example   def c1        print   Executed c1      return False def c2        print   Executed c2      return False   print  simple and  aborts early    if c1   and c2        pass  print  print  all  executes all       if all  c1   c2          pass  print

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I suggest moving the and keyword to the second line and indenting all lines containing conditions with two spaces instead of four   if  cond1     val1  and cond2     val2    and cond3     val3  and cond4     val4        do something   This is exactly how I solve this problem in my code  Having a keyword as the first word in the line makes the condition a lot more readable  and reducing the number of spaces further distinguishes condition from action

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all  and  any  are nice for the many conditions of same type case  BUT they always evaluates all conditions  As shown in this example   def c1        print   Executed c1      return False def c2        print   Executed c2      return False   print  simple and  aborts early    if c1   and c2        pass  print  print  all  executes all       if all  c1   c2          pass  print

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if our if  amp  an else condition has to execute multiple statement inside of it than we can write like below  Every when we have if else example with one statement inside of it    Thanks it work for me      usr bin python import sys numberOfArgument  len sys argv  weblogic username     weblogic password      weblogic admin server host     weblogic admin server port       if numberOfArgument    5          weblogic username   sys argv 1          weblogic password   sys argv 2          weblogic admin server host  sys argv 3          weblogic admin server port sys argv 4  elif numberOfArgument  lt 5          print   weblogic UserName  weblogic Password and weblogic host details are Mandatory like  defalutUser  passwordForDefaultUser  t3s   server domainname 7001            weblogic username   raw input  Enter Weblogic user Name           weblogic password   raw input  Enter Weblogic user Password           weblogic admin server host   raw input  Enter Weblogic admin host            weblogic admin server port   raw input  Enter Weblogic admin port    enfelif  endIf

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I find that when I have long conditions  I often have a short code body   In that case  I just double-indent the body  thus   if  cond1     val1  and cond2     val2  and     cond3     val3  and cond4     val4            do something

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What I usually do is   if  cond1     val1  and cond2     val2  and     cond3     val3  and cond4     val4            do something   this way the closing brace and colon visually mark the end of our condition

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I think  zkanda s solution would be good with a minor twist  If you had your conditions and values in their own respective lists  you could use a list comprehension to do the comparison  which would make things a bit more general for adding condition value pairs   conditions    1  2  3  4  values    1  2  3  4  if all  c  v for c  v in zip conditions  values           do something   If I did want to hard-code a statement like this  I would write it like this for legibility   if  condition1  value1  and  condition2  value2  and       condition3  value3  and  condition4  value4     And just to throw another solution out there with an iand operator   proceed   True for c  v in zip conditions  values       proceed  amp   c  v  if proceed        do something

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You don t need to use 4 spaces on your second conditional line   Maybe use   if  cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4        do something   Also  don t forget the whitespace is more flexible than you might think   if             cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4            do something if     cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4        do something   Both of those are fairly ugly though   Maybe lose the brackets  the Style Guide discourages this though    if cond1     val1  and cond2     val2  and      cond3     val3  and cond4     val4       do something   This at least gives you some differentiation   Or even   if cond1     val1  and cond2     val2  and                          cond3     val3  and                          cond4     val4       do something   I think I prefer   if cond1     val1  and      cond2     val2  and      cond3     val3  and      cond4     val4       do something   Here s the Style Guide  which  since 2010  recommends using brackets

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Here s my very personal take  long conditions are  in my view  a code smell that suggests refactoring into a boolean-returning function method  For example   def is action  required           return  cond1     val1  and cond2     val2              and cond3     val3  and cond4     val4     Now  if I found a way to make multi-line conditions look good  I would probably find myself content with having them and skip the refactoring   On the other hand  having them perturb my aesthetic sense acts as an incentive for refactoring   My conclusion  therefore  is that multiple line conditions should look ugly and this is an incentive to avoid them

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This doesn t improve so much but     allCondsAreOK    cond1     val1  and cond2     val2  and                  cond3     val3  and cond4     val4    if allCondsAreOK     do something

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This doesn t improve so much but     allCondsAreOK    cond1     val1  and cond2     val2  and                  cond3     val3  and cond4     val4    if allCondsAreOK     do something

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Plain and simple  also passes pep8 checks   if       cond1 and     cond2        print  Hello World        In recent times I have been preferring the all and any functions  since I rarely mix And and Or comparisons this works well  and has the additional advantage of Failing Early with generators comprehension   if all       cond1      cond2          print  Hello World      Just remember to pass in a single iterable  Passing in N-arguments is not correct   Note  any is like many or comparisons  all is like many and comparisons     This combines nicely with generator comprehensions  for example     Check if every string in a list contains a substring  my list          a substring is like a string         another substring     if all  substring  in item for item in my list      print  Hello World       or  if all       substring  in item     for item in my list        print  Hello World      More on  generator comprehension

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I ve lightly modified the identifiers as fixed-width names aren t representative of real code     at least not real code that I encounter     and will belie an example s readability    if  cond1     val1  and cond22     val2  and cond333     val3  and cond4444     val4        do something   This works well for  and  and  or   it s important that they re first on the second line   but much less so for other long conditions   Fortunately  the former seem to be the more common case while the latter are often easily rewritten with a temporary variable    It s usually not hard  but it can be difficult or much less obvious readable to preserve the short-circuiting of  and   or  when rewriting    Since I found this question from your blog post about C    I ll include that my C   style is identical   if  cond1     val1  and cond22     val2  and cond333     val3  and cond4444     val4         do something

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What if we only insert an additional blank line between the condition and the body and do the rest in the canonical way?

if (cond1 == 'val1' and cond2 == 'val2' and
    cond3 == 'val3' and cond4 == 'val4'):

    do_something

p.s. I always use tabs, not spaces; I cannot fine-tune...

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You could split it into two lines  total   cond1     val  and cond2     val2  and cond3     val3  and cond4    val4 if total      do something     Or even add on one condition at a time  That way  at least it separates the clutter from the if

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You don t need to use 4 spaces on your second conditional line   Maybe use   if  cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4        do something   Also  don t forget the whitespace is more flexible than you might think   if             cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4            do something if     cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4        do something   Both of those are fairly ugly though   Maybe lose the brackets  the Style Guide discourages this though    if cond1     val1  and cond2     val2  and      cond3     val3  and cond4     val4       do something   This at least gives you some differentiation   Or even   if cond1     val1  and cond2     val2  and                          cond3     val3  and                          cond4     val4       do something   I think I prefer   if cond1     val1  and      cond2     val2  and      cond3     val3  and      cond4     val4       do something   Here s the Style Guide  which  since 2010  recommends using brackets

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I prefer this style when I have a terribly large if-condition   if       expr1     and  expr2 or expr3      and hasattr thingy1     eq         or status   HappyTimes         do stuff   else      do other stuff

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Pardon my noobness  but it happens that I m not as knowledgeable of  Python as anyone of you here  but it happens that I have found something similar when scripting my own objects in a 3D BIM modeling  so I will adapt my algorithm to that of python   The problem that I find here  is double sided    Values my seem foreign for someone who may try to decipher the script  Code maintenance will come at a high cost  if those values are changed  most probable   or if new conditions must be added  broken schema    Do to bypass all these problems  your script must go like this  param Val01   Value 01    give a meaningful name for param Val i  preferable an integer param Val02   Value 02 param Val03   Value 03 param Val04   Value 04     and     etc  conditions   0             this is a value placeholder           Add script that if true will make   conditions   conditions   param Val01    value of placeholder is updated               repeat as needed   if conditions   param Val01   param Val02   param Val03   param Val04      do something   Pros of this method    Script is readable  Script can be easy maintained  conditions is a 1 comparison operation to a sum of values that represents the desired conditions  No need for multilevel conditions   Hope it help you all

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Here s another approach   cond list     cond1     val1    cond2   val2    cond3   val3    cond4   val4    if all  eval i  for i in cond list     do something   This also makes it easy to add another condition easily without changing the if statement by simply appending another condition to the list   cond list append  cond5   val5

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I prefer this style when I have a terribly large if-condition   if       expr1     and  expr2 or expr3      and hasattr thingy1     eq         or status   HappyTimes         do stuff   else      do other stuff

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I ve been struggling to find a decent way to do this as well  so I just came up with an idea  not a silver bullet  since this is mainly a matter of taste    if bool condition1 and         condition2 and                     conditionN       foo       bar     I find a few merits in this solution compared to others I ve seen  namely  you get exactly an extra 4 spaces of indentation  bool   allowing all conditions to line up vertically  and the body of the if statement can be indented in a clear ish  way  This also keeps the benefits of short-circuit evaluation of boolean operators  but of course adds the overhead of a function call that basically does nothing  You could argue  validly  that any function returning its argument could be used here instead of bool  but like I said  it s just an idea and it s ultimately a matter of taste   Funny enough  as I was writing this and thinking about the  problem   I came up with yet another idea  which removes the overhead of a function call  Why not indicate that we re about to enter a complex condition by using extra pairs of parentheses  Say  2 more  to give a nice 2 space indent of the sub-conditions relative to the body of the if statement  Example   if    foo and       bar and       frob and       ninja bear         do stuff     I kind of like this because when you look at it  a bell immediatelly rings in your head saying  hey  there s a complex thing going on here    Yes  I know that parentheses don t help readability  but these conditions should appear rarely enough  and when they do show up  you are going to have to stop and read them carefuly anyway  because they re complex    Anyway  just two more proposals that I haven t seen here  Hope this helps someone

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I ve resorted to the following in the degenerate case where it s simply AND s or OR s   if all   cond1     val1   cond2     val2   cond3     val3   cond4     val4       if any   cond1     val1   cond2     val2   cond3     val3   cond4     val4        It shaves a few characters and makes it clear that there s no subtlety to the condition

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Here s another approach   cond list     cond1     val1    cond2   val2    cond3   val3    cond4   val4    if all  eval i  for i in cond list     do something   This also makes it easy to add another condition easily without changing the if statement by simply appending another condition to the list   cond list append  cond5   val5

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You could split it into two lines  total   cond1     val  and cond2     val2  and cond3     val3  and cond4    val4 if total      do something     Or even add on one condition at a time  That way  at least it separates the clutter from the if

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What if we only insert an additional blank line between the condition and the body and do the rest in the canonical way?

if (cond1 == 'val1' and cond2 == 'val2' and
    cond3 == 'val3' and cond4 == 'val4'):

    do_something

p.s. I always use tabs, not spaces; I cannot fine-tune...

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I think  zkanda s solution would be good with a minor twist  If you had your conditions and values in their own respective lists  you could use a list comprehension to do the comparison  which would make things a bit more general for adding condition value pairs   conditions    1  2  3  4  values    1  2  3  4  if all  c  v for c  v in zip conditions  values           do something   If I did want to hard-code a statement like this  I would write it like this for legibility   if  condition1  value1  and  condition2  value2  and       condition3  value3  and  condition4  value4     And just to throw another solution out there with an iand operator   proceed   True for c  v in zip conditions  values       proceed  amp   c  v  if proceed        do something

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Plain and simple  also passes pep8 checks   if       cond1 and     cond2        print  Hello World        In recent times I have been preferring the all and any functions  since I rarely mix And and Or comparisons this works well  and has the additional advantage of Failing Early with generators comprehension   if all       cond1      cond2          print  Hello World      Just remember to pass in a single iterable  Passing in N-arguments is not correct   Note  any is like many or comparisons  all is like many and comparisons     This combines nicely with generator comprehensions  for example     Check if every string in a list contains a substring  my list          a substring is like a string         another substring     if all  substring  in item for item in my list      print  Hello World       or  if all       substring  in item     for item in my list        print  Hello World      More on  generator comprehension

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I suggest moving the and keyword to the second line and indenting all lines containing conditions with two spaces instead of four   if  cond1     val1  and cond2     val2    and cond3     val3  and cond4     val4        do something   This is exactly how I solve this problem in my code  Having a keyword as the first word in the line makes the condition a lot more readable  and reducing the number of spaces further distinguishes condition from action

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all  and  any  are nice for the many conditions of same type case  BUT they always evaluates all conditions  As shown in this example   def c1        print   Executed c1      return False def c2        print   Executed c2      return False   print  simple and  aborts early    if c1   and c2        pass  print  print  all  executes all       if all  c1   c2          pass  print

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Personally  I like to add meaning to long if-statements  I would have to search through code to find an appropriate example  but here s the first example that comes to mind  let s say I happen to run into some quirky logic where I want to display a certain page depending on many variables   English   If the logged-in user is NOT an administrator teacher  but is just a regular teacher  and is not a student themselves      if not user isAdmin   and user isTeacher   and not user isStudent        doSomething     Sure this might look fine  but reading those if statements is a lot of work  How about we assign the logic to label that makes sense  The  label  is actually the variable name   displayTeacherPanel   not user isAdmin   and user isTeacher   and not user isStudent   if displayTeacherPanel      showTeacherPanel     This may seem silly  but you might have yet another condition where you ONLY want to display another item if  and only if  you re displaying the teacher panel OR if the user has access to that other specific panel by default   if displayTeacherPanel or user canSeeSpecialPanel        showSpecialPanel     Try writing the above condition without using variables to store and label your logic  and not only do you end up with a very messy  hard-to-read logical statement  but you also just repeated yourself  While there are reasonable exceptions  remember  Don t Repeat Yourself  DRY

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Pardon my noobness  but it happens that I m not as knowledgeable of  Python as anyone of you here  but it happens that I have found something similar when scripting my own objects in a 3D BIM modeling  so I will adapt my algorithm to that of python   The problem that I find here  is double sided    Values my seem foreign for someone who may try to decipher the script  Code maintenance will come at a high cost  if those values are changed  most probable   or if new conditions must be added  broken schema    Do to bypass all these problems  your script must go like this  param Val01   Value 01    give a meaningful name for param Val i  preferable an integer param Val02   Value 02 param Val03   Value 03 param Val04   Value 04     and     etc  conditions   0             this is a value placeholder           Add script that if true will make   conditions   conditions   param Val01    value of placeholder is updated               repeat as needed   if conditions   param Val01   param Val02   param Val03   param Val04      do something   Pros of this method    Script is readable  Script can be easy maintained  conditions is a 1 comparison operation to a sum of values that represents the desired conditions  No need for multilevel conditions   Hope it help you all

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What I usually do is   if  cond1     val1  and cond2     val2  and     cond3     val3  and cond4     val4            do something   this way the closing brace and colon visually mark the end of our condition

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I prefer this style when I have a terribly large if-condition   if       expr1     and  expr2 or expr3      and hasattr thingy1     eq         or status   HappyTimes         do stuff   else      do other stuff

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I usually use    if   cond1     val1  and cond2     val2  and      cond3     val3  and cond4     val4         do something

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Just a few other random ideas for completeness s sake   If they work for you  use them   Otherwise  you re probably better off trying something else   You could also do this with a dictionary    gt  gt  gt  x     cond1     val1    cond2     val2    gt  gt  gt  y     cond1     val1    cond2     val2    gt  gt  gt  x    y True   This option is more complicated  but you may also find it useful   class Klass object       def   init   self  some vars            initialize conditions here     def   nonzero   self           return  self cond1     val1  and self cond2     val2  and                 self cond3     val3  and self cond4     val4    foo   Klass   if foo      print  foo is true   else      print  foo is false     Dunno if that works for you  but it s another option to consider   Here s one more way   class Klass object       def   init   self            initialize conditions here     def   eq   self           return  self cond1     val1  and self cond2     val2  and                self cond3     val3  and self cond4     val4    x   Klass some values  y   Klass some other values  if x    y      print  x    y  else      print  x  y    The last two I haven t tested  but the concepts should be enough to get you going if that s what you want to go with    And for the record  if this is just a one time thing  you re probably just better off using the method you presented at first   If you re doing the comparison in lots of places  these methods may enhance readability enough to make you not feel so bad about the fact that they are kind of hacky

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All respondents that also provide multi-conditionals for the if statement is just as ugly as the problem presented  You don t solve this problem by doing the same thing     Even the PEP 0008 answer is repulsive   Here is a far more readable approach  condition   random randint 0  100    to demonstrate anti conditions    42  67  12  if condition not in anti conditions      pass   Want me to eat my words  Convince me you need multi-conditionals and I ll literally print this and eat it for your amusement

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if our if  amp  an else condition has to execute multiple statement inside of it than we can write like below  Every when we have if else example with one statement inside of it    Thanks it work for me      usr bin python import sys numberOfArgument  len sys argv  weblogic username     weblogic password      weblogic admin server host     weblogic admin server port       if numberOfArgument    5          weblogic username   sys argv 1          weblogic password   sys argv 2          weblogic admin server host  sys argv 3          weblogic admin server port sys argv 4  elif numberOfArgument  lt 5          print   weblogic UserName  weblogic Password and weblogic host details are Mandatory like  defalutUser  passwordForDefaultUser  t3s   server domainname 7001            weblogic username   raw input  Enter Weblogic user Name           weblogic password   raw input  Enter Weblogic user Password           weblogic admin server host   raw input  Enter Weblogic admin host            weblogic admin server port   raw input  Enter Weblogic admin port    enfelif  endIf

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Someone has to champion use of vertical whitespace here      if       cond1    val1      and cond2    val2      and cond3    val3           do stuff     This makes each condition clearly visible  It also allows cleaner expression of more complex conditions   if      cond1    val1      or                cond2 1    val2 1           and cond2 2  gt   val2 2           and cond2 3    bad2 3                     do more stuff     Yes  we re trading off a bit of vertical real estate for clarity  Well worth it IMO

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I know this thread is old  but I have some Python 2 7 code and PyCharm  4 5  still complains about this case   if foo is not None      if  cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4                  some comment about do something             do something   Even with the PEP8 warning  visually indented line with same indent as next logical line   the actual code is completely OK   It s not  over-indenting       there are times I wish Python would ve bit the bullet and just gone with curly braces   I wonder how many bugs have been accidentally introduced over the years due to accidental mis-indentation

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I ve resorted to the following in the degenerate case where it s simply AND s or OR s   if all   cond1     val1   cond2     val2   cond3     val3   cond4     val4       if any   cond1     val1   cond2     val2   cond3     val3   cond4     val4        It shaves a few characters and makes it clear that there s no subtlety to the condition

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I usually use    if   cond1     val1  and cond2     val2  and      cond3     val3  and cond4     val4         do something

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I ve lightly modified the identifiers as fixed-width names aren t representative of real code     at least not real code that I encounter     and will belie an example s readability    if  cond1     val1  and cond22     val2  and cond333     val3  and cond4444     val4        do something   This works well for  and  and  or   it s important that they re first on the second line   but much less so for other long conditions   Fortunately  the former seem to be the more common case while the latter are often easily rewritten with a temporary variable    It s usually not hard  but it can be difficult or much less obvious readable to preserve the short-circuiting of  and   or  when rewriting    Since I found this question from your blog post about C    I ll include that my C   style is identical   if  cond1     val1  and cond22     val2  and cond333     val3  and cond4444     val4         do something

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Pack your conditions into a list  then do smth  like   if False not in Conditions      do something

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Here s what I do  remember that  all  and  any  accepts an iterable  so I just put a long condition in a list and let  all  do the work   condition    cond1     val1   cond2     val2   cond3     val3   cond4     val4    if all condition      do something

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I find that when I have long conditions  I often have a short code body   In that case  I just double-indent the body  thus   if  cond1     val1  and cond2     val2  and     cond3     val3  and cond4     val4            do something

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I ve resorted to the following in the degenerate case where it s simply AND s or OR s   if all   cond1     val1   cond2     val2   cond3     val3   cond4     val4       if any   cond1     val1   cond2     val2   cond3     val3   cond4     val4        It shaves a few characters and makes it clear that there s no subtlety to the condition

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if cond1     val1  and        cond2     val2  and        cond3     val3  and        cond4     val4         do something   or if this is clearer     if cond1     val1        and cond2     val2        and cond3     val3        and cond4     val4         do something   There is no reason indent should be a multiple of 4 in this case  e g  see  Aligned with opening delimiter    http   google-styleguide googlecode com svn trunk pyguide html showone Indentation Indentation

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Someone has to champion use of vertical whitespace here      if       cond1    val1      and cond2    val2      and cond3    val3           do stuff     This makes each condition clearly visible  It also allows cleaner expression of more complex conditions   if      cond1    val1      or                cond2 1    val2 1           and cond2 2  gt   val2 2           and cond2 3    bad2 3                     do more stuff     Yes  we re trading off a bit of vertical real estate for clarity  Well worth it IMO

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Just a few other random ideas for completeness s sake   If they work for you  use them   Otherwise  you re probably better off trying something else   You could also do this with a dictionary    gt  gt  gt  x     cond1     val1    cond2     val2    gt  gt  gt  y     cond1     val1    cond2     val2    gt  gt  gt  x    y True   This option is more complicated  but you may also find it useful   class Klass object       def   init   self  some vars            initialize conditions here     def   nonzero   self           return  self cond1     val1  and self cond2     val2  and                 self cond3     val3  and self cond4     val4    foo   Klass   if foo      print  foo is true   else      print  foo is false     Dunno if that works for you  but it s another option to consider   Here s one more way   class Klass object       def   init   self            initialize conditions here     def   eq   self           return  self cond1     val1  and self cond2     val2  and                self cond3     val3  and self cond4     val4    x   Klass some values  y   Klass some other values  if x    y      print  x    y  else      print  x  y    The last two I haven t tested  but the concepts should be enough to get you going if that s what you want to go with    And for the record  if this is just a one time thing  you re probably just better off using the method you presented at first   If you re doing the comparison in lots of places  these methods may enhance readability enough to make you not feel so bad about the fact that they are kind of hacky

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This doesn t improve so much but     allCondsAreOK    cond1     val1  and cond2     val2  and                  cond3     val3  and cond4     val4    if allCondsAreOK     do something

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all  and  any  are nice for the many conditions of same type case  BUT they always evaluates all conditions  As shown in this example   def c1        print   Executed c1      return False def c2        print   Executed c2      return False   print  simple and  aborts early    if c1   and c2        pass  print  print  all  executes all       if all  c1   c2          pass  print

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You don t need to use 4 spaces on your second conditional line   Maybe use   if  cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4        do something   Also  don t forget the whitespace is more flexible than you might think   if             cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4            do something if     cond1     val1  and cond2     val2  and         cond3     val3  and cond4     val4        do something   Both of those are fairly ugly though   Maybe lose the brackets  the Style Guide discourages this though    if cond1     val1  and cond2     val2  and      cond3     val3  and cond4     val4       do something   This at least gives you some differentiation   Or even   if cond1     val1  and cond2     val2  and                          cond3     val3  and                          cond4     val4       do something   I think I prefer   if cond1     val1  and      cond2     val2  and      cond3     val3  and      cond4     val4       do something   Here s the Style Guide  which  since 2010  recommends using brackets

[python] Styling multi-line conditions in 'if' statements?

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