CODEWITHSUNDEEP
pythontimestrftime
van
van

Reputation: 600

strftime formatting - what am I doing wrong?

I've got a string 3:01 AM - 18 Dec 2017

I've written the following pattern strftime('%-I:%M %p - %-d %b %Y') and I can't seem to get it to work, following this

My notes:

df['tweet_date'] = pd.to_datetime(df['tweet_date'], errors='coerce').apply(lambda x: x.strftime('%I:%M %p - %d %b %Y')if not pd.isnull(x) else '')

On another dataframe with a similar column this works:

df2['created_at'] = pd.to_datetime(df2['created_at'], errors='coerce').apply(lambda x: x.strftime('%Y-%m-%d %H:%M:%S')if not pd.isnull(x) else '')
df2['created_at'] = df2['created_at'].astype('datetime64[s]')`

where values before formatting look like this for example 2017-10-03T15:48:10.000Z

Upvotes: 0

Views: 1512

Answers (4)

van
van

Reputation: 600

I wanted to figure out how to use strftime in a lambda function or better, using the .dt accessor after the column in my dataframe had been converted to a datetime

I couldn't figure this out so I went for the next fastest method

from datetime import datetime
formatted_dates = []
for item in df.tweet_date:
    formatted_dates.append(datetime.strptime(item,"%I:%M %p - %d %b %Y"))
df.tweet_date = formatted_dates

Upvotes: 0

Chillie
Chillie

Reputation: 1485

Your format is fine but some os's can't use the negative formatting for zero-padded units. datetime should be able to parse both padded and non-padded instances of those just fine:

from datetime import datetime as dt

z_time = '06:48 PM - 03 Jun 2021'
nz_time = '6:48 PM - 3 Jun 2021'

dt.strptime(z_time, '%I:%M %p - %d %b %Y')
[out:] datetime.datetime(2021, 6, 3, 18, 48)

dt.strptime(nz_time, '%I:%M %p - %d %b %Y')
[out:] datetime.datetime(2021, 6, 3, 18, 48)

And since you're getting strings from datetimes, you should look whether your os supports certain formatting rules. Here's one for windows.

Upvotes: 1

BoarGules
BoarGules

Reputation: 16942

To turn your string into a time, do this:

>>> import time
>>> s  = "3:01 AM - 18 Dec 2017"
>>> time.strptime(s,'%I:%M %p - %d %b %Y')
time.struct_time(tm_year=2017, tm_mon=12, tm_mday=18, tm_hour=3, tm_min=1, 
tm_sec=0, tm_wday=0, tm_yday=352, tm_isdst=-1)

No hyphens after %. The are not mentioned in the official Python documentation.

Upvotes: 2

Sarvesh Chitko
Sarvesh Chitko

Reputation: 168

from datetime import datetime
str="3:01 AM - 18 Dec 2017"
date=datetime.strptime(str,"%I:%M %p - %d %b %Y")

Upvotes: 1

Related Questions