A date loop problem and list remove problem on JupyterLab

Question

Hello everyone, I encountered a date looping problem on JupyterLab, the problem is as shown in the attached picture:

It is very strange that the red circle of B should be displayed the same as the red circle of A. Why is week 6 missing?

And "if d.weekday() in [5, 6]: dates.remove(d)". It should be 5 and 6 removed, how can there be 4/3 and 4/10?

I have restarted the core and the result is the same. It's amazing...

Answer 1

You should not modify the list dates while iterating over it. Please check Strange result when removing item from a list while iterating over it for more details.

To removes dates which are Saturdays or Sundays, try this:

import pandas as pd 
from datetime import datetime
from datetime import timedelta

d = datetime(2022, 4, 1)
dates = [d + timedelta(days=idx) for idx in range(10)]

for d in dates:
    print(f'{d.date()}  {d.weekday()}' )

new_dates = dates.copy()
for d in dates:
    if d.weekday() in [5, 6]:
        new_dates.remove(d)

print("Removed Saturdays and Sundays!")

for d in new_dates:
    print(f'{d.date()}  {d.weekday()}' )

This gives:

2022-04-01  4
2022-04-02  5
2022-04-03  6
2022-04-04  0
2022-04-05  1
2022-04-06  2
2022-04-07  3
2022-04-08  4
2022-04-09  5
2022-04-10  6
Removed Saturdays and Sundays!
2022-04-01  4
2022-04-04  0
2022-04-05  1
2022-04-06  2
2022-04-07  3
2022-04-08  4