How to change the values of a DataFrame column with Pandas using Python
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By default you can edit the value of a Pandas Series using the DataFrame.apply() method.
This method can perform row by row or column by column operations.
And you can either work with lambda functions or apply a method directly.
Here is the code
# To work with dataframes
import pandas as pd
# We create a sample dataframe
df = pd.DataFrame({"col1" : [0, 10, 3, 11, 3, 12]})
# How to change the values of a DataFrame Series
df["col1"] = df["col1"].apply(lambda x: x + 2)
print(df["col1"])
def multiply_by_two(x):
"""Multiplies x by two"""
return x * 2
# Now we apply the method by specifying the method
# directly instead of a lambda
df["col1"] = df["col1"].apply(multiply_by_two)
print(df["col1"])
def multiply_by_n(x, n):
"""Multiplies x by n"""
return x * n
# Now we pass a method along with an argument required
# by the multiply_by_n method
df["col1"] = df["col1"].apply(multiply_by_n, n=2)
print(df["col1"])
Here you are! You now know how to change the values of a DataFrame Column with Pandas using Python!
More on DataFrames
If you want to know more about DataFrame and Pandas. Check out the other articles I wrote on the topic, just here :
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