Breaking News: Grepper is joining You.com. Read the official announcement!

How to deal with SettingWithCopyWarning in Pandas

Worried Wren answered on May 29, 2022 Popularity 8/10 Helpfulness 1/10

answer How to deal with SettingWithCopyWarning in Pandas

How to deal with SettingWithCopyWarning in Pandas

Comment

return (
    pd.read_csv(StringIO(str_of_all), sep=',', names=list('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefg')) #dtype={'A': object, 'B': object, 'C': np.float64}
    .rename(columns={'A':'STK', 'B':'TOpen', 'C':'TPCLOSE', 'D':'TPrice', 'E':'THigh', 'F':'TLow', 'I':'TVol', 'J':'TAmt', 'e':'TDate', 'f':'TTime'}, inplace=True)
    .ix[:,[0,3,2,1,4,5,8,9,30,31]]
    .assign(
        TClose=lambda df: df['TPrice'],
        RT=lambda df: 100 * (df['TPrice']/quote_df['TPCLOSE'] - 1),
        TVol=lambda df: df['TVol']/TVOL_SCALE,
        TAmt=lambda df: df['TAmt']/TAMT_SCALE,
        STK_ID=lambda df: df['STK'].str.slice(13,19),
        STK_Name=lambda df: df['STK'].str.slice(21,30)#.decode('gb2312'),
        TDate=lambda df: df.TDate.map(lambda x: x[0:4]+x[5:7]+x[8:10]),
            )
)
'''
Using Assign. From the documentation: Assign new columns to a DataFrame, returning a 
new object (a copy) with all the original columns in addition to the new ones.

See Tom Augspurger's article on method chaining in pandas:
https://tomaugspurger.github.io/method-chaining
'''

Popularity 8/10 Helpfulness 1/10 Language python

Source: stackoverflow.com

Tags: pandas python

Link to this answer
Share Copy Link