Missing Value Ratio with Pandas

mvr_pandas.py

from __future__ import division
import pandas as pd


def missing_value_ratio(pd_series):
    """
    :param pd_series: a Pandas Series object
    :return ratio: float ; missing value ratio
    Find the missing value ratio.
    missing value ratio = no of missing value / total number of rows
    no of missing value is the count of np.NaN in a Pandas Series
    """
    return pd_series.isnull().sum() / pd_series.count()


if __name__ == "__main__":
	data = pd.read_csv("airquality.csv")
	for column in data.columns:
		print col,"\t",missing_value_ratio(data[column])