pandas unique count code example

Example 1: count unique pandas

df['column'].nunique()

Example 2: return count of unique values pandas

#TO count repetition of each unique values(to find How many times the same-
# unique value is appearing in the data)

item_counts = df["Your_Column"].value_counts()
#Returns Dictionary => {"Value_name" : number_of_appearences}

Example 3: count values pandas

>>> index = pd.Index([3, 1, 2, 3, 4, np.nan])
>>> index.value_counts()
3.0    2
4.0    1
2.0    1
1.0    1
dtype: int64

Example 4: get count of unique values in column pandas

df = df.groupby('domain')['ID'].nunique()

print (df)
domain
'facebook.com'    1
'google.com'      1
'twitter.com'     2
'vk.com'          3
Name: ID, dtype: int64

Example 5: unique values in dataframe column count

df.groupby('mID').agg(['count', 'size', 'nunique']).stack()


             dID  hID  uID
mID                       
A   count      5    5    5
    size       5    5    5
    nunique    3    5    5
B   count      2    2    2
    size       2    2    2
    nunique    2    2    2
C   count      1    1    1
    size       1    1    1
    nunique    1    1    1

Example 6: values of unique from dataframe with count

data = df.groupby('ColumnName')['IDColumnName'].nunique()
print(data)