CODEWITHSUNDEEP
pythonpandas
Sheron
Sheron

Reputation: 615

Python extract a week number from the specific date

I would like to extract a week number from a data in panda dataframe but starting from the SPECIFIC date.

For example from 4th April:

20/04/2010 --> 1

27/04/2010 --> 2

04/05/2010 --> 3

and so on..

Any idea?

Thank you in advance!

Upvotes: 2

Views: 1107

Answers (2)

jeffery_the_wind
jeffery_the_wind

Reputation: 18188

Use pandas to_datetime to parse your date column if it is not already in datetime format.

http://pandas.pydata.org/pandas-docs/stable/generated/pandas.to_datetime.html

Then use the date time method weekday.

https://docs.python.org/2/library/datetime.html

my_dataframe['week_nums'] = pandas.to_datetime(my_dataframe['date_col']).weekday()

Sorry I saw you want week day from specific date, will update answer... it is easy to calculate the difference between 2 dates.

Upvotes: 1

Eric Duminil
Eric Duminil

Reputation: 54223

Just calculate the difference in days between 2 dates, divide by 7 and add 1 :

from datetime import date

origin = date(2010, 4, 20)

def week_number_from(my_date, origin):
    return (my_date - origin).days / 7 + 1

Upvotes: 2

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