Question

Which of the following denotes a missing value in a DataFrame?

• A. NULL
• B. 0
• C. NaN
• D. -1

Hint:

In pandas, \texttt{NaN} is often used for missing data, and it can be easily handled using methods such as \texttt{isna()} or \texttt{fillna()} to check and fill missing values, respectively.

Answer 1

The Correct Option is C

In a DataFrame, missing values are typically represented by \texttt{NaN}, which stands for "Not a Number." It is used in pandas to denote missing or undefined values. While \texttt{NULL} might be used in databases, and \texttt{0} and \texttt{-1} are numeric values, \texttt{NaN} is the standard representation for missing values in pandas DataFrames. Therefore, the correct answer is \texttt{NaN}.