Pandas Interview Questions and Answers

Ques 1. Explain the use of merge() in Pandas.

merge() is used to combine two DataFrames based on a common column.

Example:

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

Ques 2. How to handle missing values in a DataFrame?

You can use methods like dropna() to remove missing values or fillna() to fill them with a specific value.

Example:

df.dropna() or df.fillna(value)

Ques 3. How to rename columns in a DataFrame?

You can use the rename() method to rename columns: df.rename(columns={'OldName': 'NewName'})

Ques 4. Explain the concept of MultiIndex in Pandas.

MultiIndex allows you to have multiple index levels on an axis.

Ques 5. How to handle time series data in Pandas?

Pandas provides the Timestamp type and functions like resample() for time series analysis.

Example:

df['Date'] = pd.to_datetime(df['Date'])

Ques 6. Explain the purpose of the cut() function in Pandas.

cut() is used to segment and sort data values into bins.

Example:

pd.cut(df['Values'], bins=[0, 10, 20, 30], labels=['<10', '10-20', '20-30'])