count nan values pandas code example

Example 1: count nan pandas

#Python, pandas
#Count missing values for each column of the dataframe df

df.isnull().sum()

Example 2: find position of nan pandas

# position of NaN values in terms of index
df.loc[pandas.isna(df["b"]), :].index

# position of NaN values in terms of rows that cotnain NaN
df.loc[pandas.isna(df["b"]), :]

Example 3: df count missing values

In [5]: df = pd.DataFrame({'a':[1,2,np.nan], 'b':[np.nan,1,np.nan]})

In [6]: df.isna().sum()
Out[6]:
a    1
b    2
dtype: int64

Example 4: to detect if a data frame has nan values

df.isnull().sum().sum()
5

Example 5: find the number of nan per column pandas

In [1]: s = pd.Series([1,2,3, np.nan, np.nan])

In [4]: s.isna().sum()   # or s.isnull().sum() for older pandas versions
Out[4]: 2

Example 6: how to get the amount of nan values in a data fram

#where A is the name of the column
#where df is the name of the dataframe
count = df["A"].isna().sum()