Python Pandas вопросы и ответы для интервью

Вопрос 6. How do you select specific columns from a DataFrame?

df[['column1', 'column2']]

Вопрос 7. Explain the use of the groupby function in Pandas.

groupby is used to split the data into groups based on some criteria and then apply a function to each group independently.

Example:

df.groupby('column1').mean()

Вопрос 8. How do you handle missing data in a DataFrame?

df.dropna() or df.fillna(value)

Вопрос 9. What is the purpose of the merge function in Pandas?

merge is used to combine two DataFrames based on a common column or index.

Example:

pd.merge(df1, df2, on='common_column')

Вопрос 10. Explain the pivot_table function in Pandas.

pivot_table is used to create a spreadsheet-style pivot table as a DataFrame.

Example:

pd.pivot_table(df, values='value', index='index_column', columns='column_to_pivot')