If time is between time then change to 'daytime'-CodePudding

What I am trying to do is if 07:30:00 between 20:00:00 = daylight

And this doesn't work because of the leading zeros:

df.loc[df['Time_of_Day'] <= 07:30:00 and df['Time_of_Day'] <= 20:00:00]='daylight'

Dataframe

Time_of_Day
13:30:00
11:30:00
00:01:00
etc.

CodePudding user response：

you need to use parenthesis and quotes like this :

df.loc[(df['Time_of_Day'] >= '07:30:00') & (df['Time_of_Day'] <= '20:00:00'), 'Time_of_Day'] = 'daylight'

                     Date              Description Time_of_Day
0  09/05/2015 01:30:00 PM  DOMESTIC BATTERY SIMPLE    daylight
1  09/04/2015 11:30:00 AM           POCKET-PICKING    daylight
2  09/01/2018 12:01:00 AM                OVER $500    00:01:00
3  09/05/2015 12:45:00 PM    POSS: HEROIN(BRN/TAN)    daylight
4  09/05/2015 01:00:00 PM                   SIMPLE    daylight

(and i guess >= 7:30 instead of <=)

CodePudding user response：

# create a time field from datetime
df['time']=pd.to_datetime(df['Date']).dt.strftime('%H:%M:%S')

# use LOC to identify the rows matching criteria then set a field to 'daylight'
# i created a column named daylight, which could be anything
df.loc[(df['time']>='07:00:00') &
       (df['time']<='20:00:00'), 'daylight'] = 'daylight'
df

                     Date   Description                 Time_of_Day     time    daylight
0   09/05/2015 01:30:00 PM  DOMESTIC BATTERY SIMPLE     13:30:00    13:30:00    daylight
1   09/04/2015 11:30:00 AM  POCKET-PICKING              11:30:00    11:30:00    daylight
2   09/01/2018 12:01:00 AM  OVER $500                   00:01:00    00:01:00    NaN
3   09/05/2015 12:45:00 PM  POSS: HEROIN(BRN/TAN)       12:45:00    12:45:00    daylight
4   09/05/2015 01:00:00 PM  SIMPLE                       13:00:0            13:00:00    daylight