user1107049 user1107049 - 3 months ago 13
Python Question

How to check if character exists in DataFrame cell

After creating the three-rows DataFrame:

import pandas as pd
df = pd.DataFrame({'a': ['1-2', '3-4', '5-6']})


I check if there is any cell equal to '3-4':

df['a']=='3-4'


enter image description here

Since
df['a']=='3-4'
command results to
pandas.core.series.Series
object I can use it to create a "filtered" version of the original DataFrame like so:

filtered = df[ df['a']=='3-4' ]


enter image description here

In Python I can check for the occurrence of the string character in another string using:

string_value = '3-4'
print('-' in string_value)


What would be a way to accomplish the same while working with DataFrames?

So, I could create the filtered version of the original DataFrame by
checking if '-' character in every row's cell, like:

filtered = df['-' in df['a']]


But this syntax above is invalid and throws
KeyError: False
error message.

Answer

Use str and contains:

In [5]: df['a'].str.contains('-')
Out[5]: 
0    True
1    True
2    True
Name: a, dtype: bool