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

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

Set copy warning ： Try to be in DataFrame Set the value on the slice copy in

Because when I modify the value of each row according to the column , Modify as follows , Although it has been modified successfully

j = 0
for i in age_days:
    tample['age_days'][j] = i.days    Warning ：SettingWithCopyWarning:  A value is trying to be set on a copy of a slice from a DataFrame
    j += 1

But its utility loc Just fine ：

#  Definition j To specify the row to modify 
j = 0
for i in age_days:   #  Traverse age_days The number of days between each line in 
    #  Designate the j Yes 'age_days' Data at column   The assignment is  i.days ,i.days Just get the number of days 
    tample.loc[j, 'age_days'] = i.days
    j += 1