.interpolate()

The .interpolate() method is a function in pandas library that is used to fill missing values in a DataFrame or Series. It returns a new DataFrame or Series with the missing values filled in by interpolation.

Interpolation is the process of estimating missing values from the available data by using various mathematical techniques. The .interpolate() method supports linear, polynomial, and spline interpolation methods.

Syntax: DataFrame.interpolate(method='linear', axis=0, limit=None, inplace=False, limit_direction=None, limit_area=None, downcast=None, **kwargs)

Parameters:
method: Interpolation technique to use (default is linear)
axis: Axis to interpolate along (default is 0)
limit: Maximum number of consecutive NaN values to fill (default is None, meaning no limit)
inplace: Whether to modify the DataFrame in place (default is False)
limit_direction: Direction to limit consecutive NaN values (default is None, meaning both directions)
limit_area: Area to limit consecutive NaN values (default is None, meaning all areas)
downcast: Type of output to downcast (default is None, meaning no downcasting)

Returns: Interpolated DataFrame or Series