Print a list of space-separated elements in Python 3

Question

I have a list L of elements  say natural numbers   I want to print them in one line with a single space as a separator   But I don t want a space after the last element of the list  or before the first    In Python 2  this can easily be done with the following code   The implementation of the print statement  mysteriously  I must confess  avoids to print an extra space before the newline   L    1  2  3  4  5  for x in L      print x  print   However  in Python 3 it seems that the  supposedly  equivalent code using the print function produces a space after the last number   L    1  2  3  4  5  for x in L      print x  end      print     Of course there are easy answers to my question   I know I can use string concatenation   L    1  2  3  4  5  print     join str x  for x in L     This is a quite good  solution  but compared to the Python 2 code I find it counter-intuitive and definitely slower   Also  I know I can choose whether to print a space or not myself  like   L    1  2  3  4  5  for i  x in enumerate L       print     if i gt 0 else     x  sep     end     print     but again this is worse than what I had in Python 2   So  my question is  am I missing something in Python 3   Is the behavior I m looking for supported by the print function

User · Answer

list    1  2  3  4  5  for i in list 0 -1       print i  end       print list -1     do for loops really take that much longer to run   was trying to make something that printed all str values in a list separated by commas  inserting  and  before the last entry and came up with this   spam     apples    bananas    tofu    cats   for i in spam 0 -1       print i  end       print  and     spam -1

User · Answer

Although the accepted answer is absolutely clear  I just wanted to check efficiency in terms of time   The best way is to print joined string of numbers converted to strings   print     join list map str l       Note that I used map instead of loop  I wrote a little code of all 4 different ways to compare time   import time as t  a  b   10  210000 l   list range a  b   tic   t time   for i in l      print i  end       print   tac   t time   t1    tac - tic    1000 print  l  toe   t time   t2    toe - tac    1000 print     join  str i  for i in l    joe   t time   t3    joe - toe    1000 print     join list map str  l     toy   t time   t4    toy - joe    1000 print  Time  t1 t2 t3 t4    Result      Time 74344 76  71790 83  196 99  153 99   The output was quite surprising to me  Huge difference of time in cases of  loop method  and  joined-string method    Conclusion  Do not use loops for printing list if size is too large  in order of 10  5 or more

User · Answer

Joining elements in a list space separated   word     test    crust    must    fest   word reverse   joined string      for w in word     joined string   w   joined string       print joined string rstrim

User · Answer

You can apply the list as separate arguments   print  L    and let print   take care of converting each element to a string  You can  as always  control the separator by setting the sep keyword argument    gt  gt  gt  L    1  2  3  4  5   gt  gt  gt  print  L  1 2 3 4 5  gt  gt  gt  print  L  sep       1  2  3  4  5  gt  gt  gt  print  L  sep   - gt     1 - gt  2 - gt  3 - gt  4 - gt  5   Unless you need the joined string for something else  this is the easiest method  Otherwise  use str join     joined string       join  str v  for v in L   print joined string    do other things with joined string   Note that this requires manual conversion to strings for any non-string values in L

[python] Print a list of space-separated elements in Python 3

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