8 different ways to get column names from pandas DataFrame

Renesh Bedre    1 minute read

In this article, I will discuss the different ways to get the column names in pandas DataFrame

First, create a pandas DataFrame

import pandas as pd
df = pd.DataFrame({'col1':['A', 'B', 'C', 'D', 'E'], 'col2':[1, 2, 3, 4, 5], 'col3':[0.1, 0.2, 0.3, 0.4, 0.5]})
df.head(2)
# output
  col1  col2  col3
0    A     1   0.1
1    B     2   0.2

Now, let’s check different methods to get the column names from pandas DataFrame

Get column names using list function

list(df)
# output
['col1', 'col2', 'col3']

Get column names using * iterable unpacking operator

# it works in Python >=3.5
# as a list
[*df]
# output
['col1', 'col2', 'col3']

# as a tuple
*df,
# output
('col1', 'col2', 'col3')

# as a set
{*df}
# output
{'col3', 'col2', 'col1'} # Note: column names are not in original order

Get column names using DataFrame columns attribute

It returns pandas index

df.columns
# output
Index(['col1', 'col2', 'col3'], dtype='object')

# column names as a list
list(df.columns) 
# output
['col1', 'col2', 'col3']

df.columns.tolist() # Note: this is fastest method
# output
['col1', 'col2', 'col3']

Get column names using DataFrame columns.values method

This method returns the column names as NumPy array

df.columns.values
# output
array(['col1', 'col2', 'col3'], dtype=object)

Get column names using sorted function

This method returns the column names as a list in alphabetical order

sorted(df)
# output
['col1', 'col2', 'col3'] # Note: column names are not in original order

Get column names using keys() function

It returns pandas index

df.keys()
# output
Index(['col1', 'col2', 'col3'], dtype='object')

Get column names using list comprehension

print([col_name for col_name in df])
# output
['col1', 'col2', 'col3']

Get column names and their data types

df.dtypes
# output
col1     object
col2      int64
col3    float64
dtype: object

References

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If you have any questions, comments or recommendations, please email me at reneshbe@gmail.com

This work is licensed under a Creative Commons Attribution 4.0 International License

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