Transfer pandas dataframe column names to dictionary

Question

I'm trying to convert a pandas dataframe column names into a dictionary. Not so worried about the actual data in the dataframe.

Say I have an example dataframe like this and I'm not too worried about index just now:

Col1 Col2 Col3 Col4
--------------------
 a    b    c    a
 b    d    e    c

I'd like to get an output of a dictionary like:

{'Col1': 0, 'Col2': 1, 'Col3': 2, 'Col4': 3}

Not too worried about the order they get printed out, as long as the assigned keys in the dictionary keep the order for each column name's order.

Answer 1

That is straight forward with a comprehension as:

Code:

{c: i for i, c in enumerate(df.columns)}

Test Code:

import pandas as pd

df = pd.DataFrame({'date': ['2015-01-01', '2015-01-02', '2015-01-03'],
                   'value': ['a', 'b', 'c'],
                   'num': [1, 2, 3]
                   })

print(df)
print({c: i for i, c in enumerate(df.columns)})

Results:

         date  num value
0  2015-01-01    1     a
1  2015-01-02    2     b
2  2015-01-03    3     c

{'date': 0, 'num': 1, 'value': 2}

Answer 2

Instead of using enumerate as @StephenRauch has posted, you could also use a pandas.Index method, get_loc:

{i:df.columns.get_loc(i) for i in df.columns}

Using Stephen's setup:

import pandas as pd

df = pd.DataFrame({'date': ['2015-01-01', '2015-01-02', '2015-01-03'],
                   'value': ['a', 'b', 'c'],
                   'num': [1, 2, 3]
                   })

print(df)
print({i:df.columns.get_loc(i) for i in df.columns})

Output:

         date value  num
0  2015-01-01     a    1
1  2015-01-02     b    2
2  2015-01-03     c    3

{'date': 0, 'value': 1, 'num': 2}