How to check if a column exists in Pandas How to check if a column exists in Pandas python python

How to check if a column exists in Pandas


This will work:

if 'A' in df:

But for clarity, I'd probably write it as:

if 'A' in df.columns:


To check if one or more columns all exist, you can use set.issubset, as in:

if set(['A','C']).issubset(df.columns):   df['sum'] = df['A'] + df['C']                

As @brianpck points out in a comment, set([]) can alternatively be constructed with curly braces,

if {'A', 'C'}.issubset(df.columns):

See this question for a discussion of the curly-braces syntax.

Or, you can use a list comprehension, as in:

if all([item in df.columns for item in ['A','C']]):


Just to suggest another way without using if statements, you can use the get() method for DataFrames. For performing the sum based on the question:

df['sum'] = df.get('A', df['B']) + df['C']

The DataFrame get method has similar behavior as python dictionaries.


matomo