Datetime comparison using f strings in python

Question

Consider the following dataframe

Y = pd.DataFrame([("2021-10-11","john"),("2021-10-12","wick")],columns = ['Date','Name'])
Y['Date'] = pd.to_datetime(Y['Date'])

Now consider the following code snippet in which I try to print slices of the dataframe filtered on the column "Date". However, it prints a empty dataframe

for date in set(Y['Date']):
    print(Y.query(f'Date == {date.date()}'))

Essentially, I wanted to filter the dataframe on the column "Date" and do some processing on that in the loop. How do I achieve that?

What do you want to do and how do you want to filter the dates ? — Gedas Miksenas, Nov 09 '21 at 09:09

jezrael · Answer 1 · 2021-11-10T07:17:40.087

1

Use "" because f-strings removed original "" and error is raised:

Y = pd.DataFrame([("2021-10-11","john"),("2021-10-12","wick")],columns = ['Date','Name'])

Y['Date'] = pd.to_datetime(Y['Date'])


for date in set(Y['Date']):
    print(Y.query(f'Date == "{date}"'))

edited Nov 10 '21 at 07:17

answered Nov 09 '21 at 09:13

jezrael

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why does repr return a string representation that is comparable? just curious. – dineshdileep Nov 09 '21 at 09:22
@dineshdileep - checked again and change solution by [this](https://stackoverflow.com/a/53609728/2901002) – jezrael Nov 10 '21 at 07:18

Roxy · Accepted Answer · 2021-11-09T09:22:32.443

1

The date needs to be accessed at the following query command:

Y = pd.DataFrame([("2021-10-11","john"),("2021-10-12","wick")],columns = ['Date','Name'])
for date in set(Y['Date']):
    print(Y.query('Date == @date'))

edited Nov 09 '21 at 09:22

answered Nov 09 '21 at 09:15

Roxy

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what is the need to define "date_to_be_queried"? – dineshdileep Nov 09 '21 at 09:21
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its an artifact of the implementation, its removed thanks. – Roxy Nov 09 '21 at 09:23

Datetime comparison using f strings in python

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