Marking the entire group if condition is true for a single row
For improve performance dont use groupby, rather get all WeekNum with at least one 1 and then select values by isin, last cast boolean mask to ints:
weeks = df.loc[df['Public_Holiday'].eq(1), 'WeekNum']
df['Public_Holiday_Week'] = df['WeekNum'].isin(weeks).astype(int)
print (df)
Date WeekNum Public_Holiday Public_Holiday_Week
0 1/1/2015 1 1 1
1 2/1/2015 1 0 1
2 3/1/2015 1 0 1
3 4/1/2015 1 0 1
4 5/1/2015 1 0 1
5 6/1/2015 1 0 1
6 7/1/2015 1 0 1
7 8/1/2015 2 0 0
8 9/1/2015 2 0 0
9 10/1/2015 2 0 0
10 11/1/2015 2 0 0
11 12/1/2015 2 0 0
12 13/1/2015 2 0 0
As pointed @Mohamed Thasin ah if necessary is possible groupby by week, but then get different output, because different week numbers:
df['weeks'] = pd.to_datetime(df['Date'], dayfirst=True).dt.week
weeks = df.loc[df['Public_Holiday'].eq(1), 'weeks']
df['Public_Holiday_Week'] = df['weeks'].isin(weeks).astype(int)
print (df)
Date WeekNum Public_Holiday weeks Public_Holiday_Week
0 1/1/2015 1 1 1 1
1 2/1/2015 1 0 1 1
2 3/1/2015 1 0 1 1
3 4/1/2015 1 0 1 1
4 5/1/2015 1 0 2 0
5 6/1/2015 1 0 2 0
6 7/1/2015 1 0 2 0
7 8/1/2015 2 0 2 0
8 9/1/2015 2 0 2 0
9 10/1/2015 2 0 2 0
10 11/1/2015 2 0 2 0
11 12/1/2015 2 0 3 0
12 13/1/2015 2 0 3 0
Use resample and skip the use of the WeekNum column altogether.
df.assign(
Public_Holiday_Week=
df.resample('W-Wed', on='Date').Public_Holiday.transform('max')
)
Date WeekNum Public_Holiday Public_Holiday_Week
0 2015-01-01 1 1 1
1 2015-01-02 1 0 1
2 2015-01-03 1 0 1
3 2015-01-04 1 0 1
4 2015-01-05 1 0 1
5 2015-01-06 1 0 1
6 2015-01-07 1 0 1
7 2015-01-08 2 0 0
8 2015-01-09 2 0 0
9 2015-01-10 2 0 0
10 2015-01-11 2 0 0
11 2015-01-12 2 0 0
12 2015-01-13 2 0 0