pandas count occurrences of unique values in column no header code example

Example 1: 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 2: 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