How can I create an array list of dictionaries in python

Question

I have a dictionary as follows     A  0  C  0  G  0  T  0    I want to create an array with many dictionaries in it  as follows      A  0  C  0  G  0  T  0    A  0  C  0  G  0  T  0    A  0  C  0  G  0  T  0         This is my code   weightMatrix      for k in range motifWidth       weightMatrix k      A  0  C  0  G  0  T  0    But of course it isn t working  Can someone give me a hint  Thanks

User · Answer

weightMatrix      A  0  C  0  G  0  T  0  for k in range motifWidth

User · Answer

Try this   lst        use append to add items to the list   lst append   A  0  C  0  G  0  T  0   lst append   A  1  C  1  G  1  T  1      if u need to add n no of items to the list  use range with append  for i in range n       lst append   A  0  C  0  G  0  T  0    print lst

User · Answer

Dictionary   dict     a   a   b   b   c   c     array of dictionary  arr    dict dict dict  arr    a    a    c    c    b    b      a    a    c    c    b    b      a    a    c    c    b    b

User · Answer

Use   weightMatrix      for k in range motifWidth       weightMatrix append   A  0  C  0  G  0  T  0

User · Answer

I assume that motifWidth contains an integer   In Python  lists do not change size unless you tell them to   Hence  Python throws an exception when you try to change an element that isn t there   I believe you want   weightMatrix      for k in range motifWidth       weightMatrix append   A  0  C  0  G  0  T  0     For what it s worth  when asking questions in the future  it would help if you included the stack trace showing the error that you re getting rather than just saying  it isn t working    That would help us directly figure out the cause of the problem  rather than trying to puzzle it out from your code   Hope that helps

User · Answer

Minor variation to user1850980 s answer  for the question  How to initialize a list of empty dictionaries   using list constructor   dictlistGOOD   list     for i in xrange listsize      I found out to my chagrin  this does NOT work   dictlistFAIL          listsize    FAIL    as it creates a list of references to the same empty dictionary  so that if you update one dictionary in the list  all the other references get updated too   Try these updates to see the difference   dictlistGOOD 0   key      value  dictlistFAIL 0   key      value     I was actually looking for user1850980 s answer to the question asked  so his her answer was helpful

User · Answer

This is how I did it and it works   dictlist    dict   for x in range n     It gives you a list of n empty dictionaries

[python] How can I create an array/list of dictionaries in python?

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