[Python] Python pandas insert list into a cell

I have a list 'abc' and a dataframe 'df':

abc = ['foo', 'bar']
df =
A B
0 12 NaN
1 23 NaN


I want to insert the list into cell 1B, so I want this result:

A B
0 12 NaN
1 23 ['foo', 'bar']


Ho can I do that?

1) If I use this:

df.ix[1,'B'] = abc


I get the following error message:

ValueError: Must have equal len keys and value when setting with an iterable


because it tries to insert the list (that has two elements) into a row / column but not into a cell.

2) If I use this:

df.ix[1,'B'] = [abc]


then it inserts a list that has only one element that is the 'abc' list ( [['foo', 'bar']] ).

3) If I use this:

df.ix[1,'B'] = ', '.join(abc)


then it inserts a string: ( foo, bar ) but not a list.

4) If I use this:

df.ix[1,'B'] = [', '.join(abc)]


then it inserts a list but it has only one element ( ['foo, bar'] ) but not two as I want ( ['foo', 'bar'] ).

Thanks for help!

EDIT


My new dataframe and the old list:

abc = ['foo', 'bar']
df2 =
A B C
0 12 NaN 'bla'
1 23 NaN 'bla bla'


Another dataframe:

df3 =
A B C D
0 12 NaN 'bla' ['item1', 'item2']
1 23 NaN 'bla bla' [11, 12, 13]


I want insert the 'abc' list into df2.loc[1,'B'] and/or df3.loc[1,'B'].

If the dataframe has columns only with integer values and/or NaN values and/or list values then inserting a list into a cell works perfectly. If the dataframe has columns only with string values and/or NaN values and/or list values then inserting a list into a cell works perfectly. But if the dataframe has columns with integer and string values and other columns then the error message appears if I use this: df2.loc[1,'B'] = abc or df3.loc[1,'B'] = abc.

Another dataframe:

df4 =
A B
0 'bla' NaN
1 'bla bla' NaN


These inserts work perfectly: df.loc[1,'B'] = abc or df4.loc[1,'B'] = abc.

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