CODEWITHSUNDEEP
python-3.xpandas
user1452494
user1452494

Reputation: 1185

Lowercasing each word in a pandas dataframe column

I'm new to pandas and have a column in a pandas dataframe that contains strings (non-lowercase) that I want to convert to lowercase. The dataframe column is called:

df['labels']

and its elements are all lists (of strings):

0     ["Cat", "Dog", "Horse"]
1     ["Pig", "Fish", "Giraffe"]
....

I would like to lower case each string in the list, intuitively I tried this:

for element in input_data['labels']:
    for word in element:
        word.lower()

but on a print(input_data["labels"] nothing was lowercased.

Upvotes: 2

Views: 1069

Answers (2)

Zero
Zero

Reputation: 76927

This would give you want you want --

df = pd.DataFrame({'Labels' : [["Cat", "Dog", "Horse"],
                               ["Pig", "Fish", "Giraffe"]]})

df['Labels'].apply(lambda x: [y.lower() for y in x])

0       [cat, dog, horse]
1    [pig, fish, giraffe]
Name: Labels, dtype: object

But, like mentioned in comments, do you need to store the data is this way?

Upvotes: 1

EdChum
EdChum

Reputation: 394101

the following would work but generally it's a bad idea to store lists as data IMO:

In [18]:

df['labels'] = df['labels'].apply(lambda x: [w.lower() for w in x])
df
Out[18]:
                 labels
0     [cat, dog, horse]
1  [pig, fish, giraffe]

Upvotes: 2

Related Questions