convert list of strings to panda dataframe with types

user_2859449 0
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I have a list of a list of numbers where two rows are strings, e.g.

A = [[1,'5.4','2'],[2,'6','3']]

How do I convert this to a pandas dataframe, such that the 1st and 3nd columns are integers and the 2nd column is a float

by

pd.DataFrame(A,dtype=float)

it converts all to floats.

pandas dataframe python
3 Answers

You could use applymap with pd.eval:

>>> df = pd.DataFrame(A).applymap(pd.eval)
>>> df
   0    1  2
0  1  5.4  2
1  2  6.0  3
>>> df.dtypes
0      int64
1    float64
2      int64
dtype: object
>>>
user_87083640

Or use pd.to_numeric:

df = pd.DataFrame(A).apply(pd.to_numeric)

>>> df
   0    1  2
0  1  5.4  2
1  2  6.0  3

>>> df.dtypes
0      int64
1    float64
2      int64
dtype: object

If you have non numeric columns, use:

pd.DataFrame(A).apply(pd.to_numeric, errors='ignore')
user_152399510

Here is a possible solution:

pd.DataFrame(A).astype({0: int, 1: float, 2: int})

If you don't want to convert everything to a string and then change the type you could do something like this (everything is loaded as a float and then later you change the dtype of a few columns to int):

pd.DataFrame(A, dtype=float).convert_dtypes()

or

pd.DataFrame(A, dtype=float).astype({0: int, 2: int})
user_52961060
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