Count the frequency that a value occurs in a dataframe column

Here is an example code snippet that counts the frequency of values in a column of a Pandas DataFrame:

import pandas as pd

# create a sample dataframe
df = pd.DataFrame({'A': [1, 2, 3, 1, 2, 3, 1, 2, 3],
                   'B': ['a', 'b', 'c', 'a', 'b', 'c', 'a', 'b', 'c']})

# count the frequency of values in column 'A'
value_counts = df['A'].value_counts()


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This will output:

1    3
2    3
3    3
Name: A, dtype: int64

You can also use .value_counts(normalize=True) to get the frequency as a percentage.