CODE EXAMPLE FOR PYTHON

selecting letters in a row

#creating a new column and segregating the items
df['Item_Identifier_Combined'] = df['Item_Identifier'].apply(lambda x: x[0:2])
df['Item_Identifier_Combined'].value_counts()

output:-
FD    10201
NC     2686
DR     1317
Name: Item_Identifier_Combined, dtype: int64