The interquartile range (IQR) is the difference between the third quartile (Q3) and the first (Q1). It measures the spread of the central 50% of values and resists extreme values. It is also used to spot outliers with the 1.5 x IQR whisker rule.
Example
iqr = df['x'].quantile(0.75) - df['x'].quantile(0.25)