I want to add an additional column to an existing dataframe that has the length of the 'seller_name' column as its value.
The output should be like so:
seller_name name_length
-------------|-------------
Rick | 4
Hannah | 6
However, I'm having difficulty getting the code right.
df['name_length'] = len(df['seller_name'])
just gives me the length of the entire column (6845) And
df['nl'] = df[len('seller_name')]
Throws a KeyError.
Does anyone know the correct command to achieve my goal?
Many thanks!
Use the .str
string accessor to perform string operations on DataFrames. In particular, you want .str.len
:
df['name_length'] = df['seller_name'].str.len()
The resulting output:
seller_name name_length
0 Rick 4
1 Hannah 6
Say you have this data:
y_1980 = pd.read_csv('y_1980.csv', sep='\t')
country y_1980
0 afg 196
1 ago 125
2 alb 23
If you want to calculate the length of any column you can use:
y_1980['length'] = y_1980['country'].apply(lambda x: len(x))
print(y_1980)
country y_1980 length
0 afg 196 3
1 ago 125 3
2 alb 23 3
This way you can calculate the length of any columns you desire.
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