Converting Dictionary to List

Question

I m trying to convert a Python dictionary into a Python list  in order to perform some calculations    My dictionary dict      dict  Capital    London  dict  Food    Fish amp Chips  dict  2012    Olympics    lists temp      dictList        My attempt  for key  value in dict iteritems        aKey   key     aValue   value     temp append aKey      temp append aValue      dictList append temp       aKey          aValue        That s my attempt at it    but I can t work out what s wrong

User · Accepted Answer

Your problem is that you have key and value in quotes making them strings  i e  you re setting aKey to contain the string  key  and not the value of the variable key   Also  you re not clearing out the temp list  so you re adding to it each time  instead of just having two items in it   To fix your code  try something like   for key  value in dict iteritems        temp    key value      dictlist append temp    You don t need to copy the loop variables key and value into another variable before using them so I dropped them out   Similarly  you don t need to use append to build up a list  you can just specify it between square brackets as shown above   And we could have done dictlist append  key value   if we wanted to be as brief as possible   Or just use dict items   as has been suggested

User · Answer

You should use dict items     Here is a one liner solution for your problem     k v  for k v in dict items      and result      Food    Fish amp Chips      2012    Olympics      Capital    London      or you can do  l     l extend  k v   for k v in dict items      for     Food    Fish amp Chips    2012    Olympics    Capital    London

User · Answer

If you re making a dictionary only to make a list of tuples  as creating dicts like you are may be a pain  you might look into using zip    Its especialy useful if you ve got one heading  and multiple rows  For instance if I assume that you want Olympics stats for countries   headers     Capital    Food    Year   countries           London    Fish  amp  Chips    2012          Beijing    Noodles    2008       for olympics in countries      print zip headers  olympics    gives     Capital    London      Food    Fish  amp  Chips      Year    2012       Capital    Beijing      Food    Noodles      Year    2008      Don t know if thats the end goal  and my be off topic  but it could be something to keep in mind

User · Answer

dict items     Does the trick

User · Answer

gt  gt  gt  a     foo    bar    baz    quux    hello    world     gt  gt  gt  list reduce lambda x  y  x   y  a items        foo    bar    baz    quux    hello    world     To explain  a items   returns a list of tuples  Adding two tuples together makes one tuple containing all elements  Thus the reduction creates one tuple containing all keys and values and then the list      makes a list from that

User · Answer

Converting from dict to list is made easy in Python  Three examples    gt  gt  d     a    Arthur    b    Belling     gt  gt  d items      a    Arthur      b    Belling      gt  gt  d keys     a    b     gt  gt  d values     Arthur    Belling

User · Answer

Probably you just want this   dictList   dict items     Your approach has two problems  For one you use key and value in quotes  which are strings with the letters  key  and  value   not related to the variables of that names  Also you keep adding elements to the  temporary  list and never get rid of old elements that are already in it from previous iterations  Make sure you have a new and empty temp list in each iteration and use the key and value variables   for key  value in dict iteritems        temp          aKey   key     aValue   value     temp append aKey      temp append aValue      dictList append temp    Also note that this could be written shorter without the temporary variables  and in Python 3 with items   instead of iteritems      for key  value in dict items        dictList append  key  value

[python] Converting Dictionary to List?

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