Python Pandas вопросы и ответы для интервью

Вопрос 11. How can you apply a function to each element in a DataFrame?

Use the apply function. df.apply(my_function)

Вопрос 12. What is the purpose of the melt function in Pandas?

melt is used to transform wide-format data to long-format data.

Example:

pd.melt(df, id_vars=['id_column'], value_vars=['value_column'])

Вопрос 13. Explain the concept of broadcasting in Pandas.

Broadcasting is the ability of NumPy and Pandas to perform operations on arrays or DataFrames of different shapes.

Вопрос 14. How can you rename columns in a Pandas DataFrame?

Use the rename function. df.rename(columns={'old_name': 'new_name'})

Вопрос 15. What is the purpose of the concat function in Pandas?

concat is used to concatenate DataFrames along a particular axis.

Example:

pd.concat([df1, df2], axis=1)