find row with nan pandas code example

Example 1: dataframe find nan rows

df[df.isnull().any(axis=1)]

Example 2: select rows with nan pandas

df[df['Col2'].isnull()]

Example 3: count rows with nan pandas

np.count_nonzero(df.isnull().values)   
 np.count_nonzero(df.isnull())           # also works

Example 4: pandas if nan, then the row above

df.fillna(method='ffill')