How can i generate a range of dates from a string and obtain another list of string in python?

Asked Sep 09 '20 at 10:18

Active Sep 09 '20 at 10:42

Viewed 43 times

I have a single date:

Data_raw = "08/09/20 21:05"

How can i generate a list of dates (type=str) included in an interval of +-40 minutes? Please note that I have already tried the following code:

    Data = datetime.strptime(Data_raw,'%d/%m/%y %H:%M')
    a = Data
    c = a + timedelta(minutes=40)
    b = a - timedelta(minutes=40)
    Upper_limit = str(pd.date_range(start=Data, end=c, periods=41))
    Lower_limit = str(pd.date_range(start=Data, end=b, periods=41))

Unfortunately when I try to filter a DataFrame with Upper_limit and Lower_limit no result is shown. On the other hand, if the filter is applied with the string (Data_raw) the DataFrame is succesfully filtered.

Thanks

edited Sep 09 '20 at 10:28

asked Sep 09 '20 at 10:18

Shold

1

What is "Data"? – tnknepp Sep 09 '20 at 10:24
also, what is your expected range of timestamps? '2020-08-09 21:05:00' - 40 min to '2020-08-09 21:05:00' + 40 min? with minute frequency? – FObersteiner Sep 09 '20 at 10:26
@tnknepp my bad, I added another missing line – Shold Sep 09 '20 at 10:29
@MrFuppes exactly – Shold Sep 09 '20 at 10:29
What is your desired output? – DirtyBit Sep 09 '20 at 10:36
Ok. How are do you "filter a DataFrame with Upper_limit and Lower_limit"? – tnknepp Sep 09 '20 at 10:37
@DirtyBit 80 dates separated by 1 minute each – Shold Sep 09 '20 at 10:40
@tnknepp df_new = df.loc[df['DATIME'] == Upper_limit] df_new_2 = df_new.loc[df_new['DATIME'] == Lower_limit] – Shold Sep 09 '20 at 10:41
Ok. What is in the "DATIME" column of your dataframe? Are these datetime values, or strings? – tnknepp Sep 09 '20 at 10:45
@tnknepp strings of dates, like Data_raw – Shold Sep 09 '20 at 10:50
it might be appropriate to convert `df['DATIME']` [to_datetime](https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.to_datetime.html) – FObersteiner Sep 09 '20 at 10:53
@Shold And there's your problem. You are comparing different types. Convert DATIME to datetime values and you are set. – tnknepp Sep 09 '20 at 10:54
@MrFuppes It is more than appropriate, it is necessary. – tnknepp Sep 09 '20 at 10:54
@tnknepp: technically, string comparison *should* work (if you cast the datetimeindex to string correctly...) but I'd recommend using datetime. – FObersteiner Sep 09 '20 at 10:56
@MrFuppes Sure. My point is you cannot compare a datetime to a string without converting one or the other. I worded that poorly. – tnknepp Sep 09 '20 at 10:59
@tnknepp oh i see so you suggest this way around, i really don't like to work with datetime sometimes it's very frustrating Or maybe I'm just a nub – Shold Sep 09 '20 at 11:05
@MrFuppes above – Shold Sep 09 '20 at 11:05
How can i convert a DatFrame column into datetime? to_datetime works fine? – Shold Sep 09 '20 at 11:06
@Shold There is probably something built into pandas that does this, but I normally use a list comprehension for this. e.g. df.DATIME = [dt.datetime.strptime(r, "%m/%d/%y %H:%M") for r in df.DATIME]. If you want to keep DATIME as strings you can always create a new column for the datetime values. – tnknepp Sep 09 '20 at 11:13
make sure to use the pandas built-in, `pandas.to_datetime`, see my comment above. You can find plenty of resources on this, also [here on SO](https://stackoverflow.com/questions/17134716/convert-dataframe-column-type-from-string-to-datetime-dd-mm-yyyy-format). – FObersteiner Sep 09 '20 at 11:56
@MrFuppes finally it's working, is there anyway to give you and tnknepp points? Thanks – Shold Sep 09 '20 at 15:51
@tnknepp as above – Shold Sep 09 '20 at 15:51

How can i generate a range of dates from a string and obtain another list of string in python?

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