find missing values in a column in pandas code example

Example 1: count missing values by column in pandas

df.isna().sum()

Example 2: check for missing values by column in pandas

df.isna().any()

Example 3: missing values in a dataset python

df.isnull().sum()

Example 4: how to filing the missing data by mean of row in dataframe in pandas

df.T.fillna(df.mean(axis=1)).T

Example 5: filling the missing data in pandas

note:to fill a specific value

varable = 1
def fill_mod_acc(most_related_coloum_name,missing_data_coloum):
    if np.isnan(missing_data_coloum):
        return varable[most_related_coloum_name]
    else:
        return missing_data_coloum

df['missing_data_coloum'] = df.apply(lambda x:fill_mod_acc(x['most_related_coloum_name'],x['missing_data_coloum']),axis=1)


Note:to fill mean from existing closley related coloum

varable = df.groupby('most_related_coloum_name').mean()['missing_data_coloum']

def fill_mod_acc(most_related_coloum_name,missing_data_coloum):
    if np.isnan(missing_data_coloum):
        return varable[most_related_coloum_name]
    else:
        return missing_data_coloum

df['missing_data_coloum'] = df.apply(lambda x:fill_mod_acc(x['most_related_coloum_name'],x['missing_data_coloum']),axis=1)