AttributeError：“ int”对象没有属性“ keys”

Question

Below are the columns in the DataFrame of data I am iterating on,

 > incident_id int64 date > object state object city_or_county > object address object n_killed > int64 n_injured int64 incident_url > object source_url object > incident_url_fields_missing bool congressional_district > float64 gun_stolen object gun_type > object incident_characteristics object latitude > float64 location_description object longitude > float64 n_guns_involved float64 notes > object participant_age object participant_age_group > object participant_gender object participant_name > object participant_relationship object participant_status > object participant_type object sources > object state_house_district float64 state_senate_district > float64 dtype: object 

and below is the code i have written,

def count_entries(df,col_name):
    """ Return a dictionary with counts of occurrences as value for each key"""
    cols_count = {}
    col = df[col_name]
    for entry in col:
        if entry in cols_count.keys():
            cols_count[entry] += 1
        else:
            cols_count = 1
    return cols_count
result = count_entries(data, 'gun_stolen')
print (result)

Answer 1

You can simplify solution with value_counts :

df = pd.DataFrame({
        'A':list('abcdef'),
         'F':list('aaabbc')
})

print (df)
   A  F
0  a  a
1  b  a
2  c  a
3  d  b
4  e  b
5  f  c

def count_entries(df,col_name):
    """ Return a dictionary with counts of occurrences as value for each key"""
    return df[col_name].value_counts().to_dict()

Or use collections.Counter :

from collections import Counter

def count_entries(df,col_name):
    """ Return a dictionary with counts of occurrences as value for each key"""
    return dict(Counter(df[col_name]))

result = count_entries(df, 'F')
print (result)
{'a': 3, 'b': 2, 'c': 1}

Answer 2

def count_entries(df,col_name):
    """ Return a dictionary with counts of occurrences as value for each key"""
    cols_count = {}
    col = df[col_name]
    for entry in col:
        if entry in cols_count.keys():
            cols_count[entry] += 1
        else:
            # you forgot the [entry] in else statement.
            cols_count[entry] = 1
    return cols_count
result = count_entries(data, 'gun_stolen')
print (result)