Function Application Continued(apply)...

Apply - Apply a function along an axis(rowwise or columnwise) of the DataFrame.
Example:-

import pandas as pd

import numpy as np

df = pd.DataFrame({'one':pd.Series([1,2,3,4]),'two':pd.Series([3,5,6,7])})

print(df)

print(df.apply(np.mean))

Output:-

one two 0 1 3 1 2 5 2 3 6 3 4 7 one 2.50 two 5.25

Explanation:-

• df is a dataframe object with some float/number data.
• df.apply(np.mean) applies mean(average) on the index(columnwise/axis=0) by default

thats why the output above.

• df.apply(np.mean,axis=1) applies mean on the columns(Rowwise) and gives output as below one    2.50

          two    5.25
Quiz:-

1. import pandas as pd

import numpy as np

df = pd.DataFrame({'one':pd.Series([1,2,3,4]),'two':pd.Series([3,5,6,7])})
print(df.apply(np.sum, axis=0))
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