如何使用来自满足条件的另一列的解析值在 dataframe 中创建新列

Question

Here is an example:

cars2 = {'Brand': ['Hon*da\nCivic', 'BM^AMT^B6^278.99\n'],
        'Price': [22000, 55000]
        }

df2 = pd.DataFrame(cars2, columns = ['Brand', 'Price'])

delim = '^'

Output:

                Brand  Price
0       Hon*da\nCivic  22000
1  BM^AMT^B6^278.99\n  55000

I need:

                Brand  Price Allowed Amount
0       Hon*da\nCivic  22000              0
1  BM^AMT^B6^278.99\n  55000         278.99

I tried:

for field in range(0, len(df2)):
    if 'AMT'+delim+'B6' in df2.iloc[field]['Brand']:
                df2.iloc[field]['Allowed_Amount'] = df2.iloc[field]['Brand'].split("AMT"+delim+"B6")[1][1:].split('\n')[0]
    else:
        df2.iloc[field]['Allowed_Amount'] = 0

It gives me this error:

__main__:5: SettingWithCopyWarning: 
A value is trying to be set on a copy of a slice from a DataFrame

How can i fix this? If there is a better way to do this, please let me know. Thanks.

Answer 1

You can do like this:

 df2['Allowed_Amount'] = df2['Brand'].str.split('^',-1).str[3]
 df2['Allowed_Amount'] = df2['Allowed_Amount'].str[:-2]

You can also make it one line:

df2['Allowed_Amount'] = df2['Brand'].str.split('^',-1).str[3].str[:-2]

The first line will split the "^" by doing from last and get the last value. Then in second line we removing the new line !