Python script: convert random date formats to fixed yyyy-mm-dd - python

I'm quite new to python and don't know much about it but i need to make a small script that when someone inputs a date in any format , it would then converts it in to yyyy-mm-dd format.
The script should be able to share elements of the entered date, and identify patterns.
It might be easy and obvious to some but making one by my self is over my head.
Thanks in advance!

This is a difficult task to do yourself; you might want to take a look at dateutil which has a rather robust parse() method that you can use to try and parse arbitrarily formatted date strings.

You can do something like this (not tested)
import locale
import datetime
...
parsedDate = datetime.strptime(your_string, locale.D_FMT)
print datetime.strftime(parsedDate, "%Y-%M-%d")
This assumes that the user will use its own local convention for dates.

You can use strftime for output (your format is "%Y-%M-%d").
For parsing input there's a corresponding function - strptime. But you won't be able to handle "any format". You have to know what you're getting in the first place. Otherwise you wouldn't be able to tell a difference between (for example) American and other dates. What does 01.02.03 mean for example? This could be:
yy.mm.dd
dd.mm.yy
mm.dd.yy

Related

Get date format code from a string/datetime using python

is there a way to find out in Python the date format code of a string?
My Input would be e.g.:
2020-09-11T17:42:33.040Z
What I am looking for is in this example to get this:
'%Y-%m-%dT%H:%M:%S.%fZ'
Point is that I have diffrent time Formats for diffrent Files, therefore I don't know in Advancce how my datetime code format will look like.
For processing my data, I need unix time format, but to calculate that I need a solution to this problem.
data["time_unix"] = data.time.apply(lambda row: (datetime.datetime.strptime(row, '%Y-%m-%dT%H:%M:%S.%fZ').timestamp()*100))
Thank you for the support!

How to specify the format of timestamp in python

I have a dataframe with dates in string format. I convert those dates to timestamp, so that I could use this date column in the later part of the code. Everything is fine with calculations/comparisons etc, but I would like the timestamp to appear in %d.%m.%Y format, as opposed to default %Y-%m-%d. Let me illustrate it -
dt=pd.DataFrame({'date':['09.12.1998','07.04.2014']},index=[1,2])
dt
Out[4]:
date
1 09.12.1998
2 07.04.2014
dt['date_1']=pd.to_datetime(dt['date'],format='%d.%m.%Y')
dt
Out[7]:
date date_1
1 09.12.1998 1998-12-09
2 07.04.2014 2014-04-07
I would like to have dt['date_1'] to de displayed in the same format as dt['date']. I don't wish to use .strftime() function because it will convert the datatype from timestamp to string.
In Nutshell: How can I invoke the python system in displaying the timestamp in the format of my choice(months could be like APR, MAY etc), rather than getting a default format(like 1998-12-09), keeping in mind that the data type remains a timestamp, rather than string?
It seems Pandas didn't implement this option yet:
https://github.com/pandas-dev/pandas/issues/11501
having a look at https://pandas.pydata.org/pandas-docs/stable/options.html looks like you can set the display to achieve some of this, although not all.
display.date_dayfirst When True, prints and parses dates with the day first, eg 20/01/2005
display.date_yearfirst When True, prints and parses dates with the year first, eg 2005/01/20
so you can have dayfirst, but they haven't included names for months.
On a more fundamental level, whenever you're displaying something it is a string, right? I'm not sure why you wouldn't be able to convert it when you're displaying it without having to change the original dataframe.
your code would be:
pd.set_option("display.date_dayfirst", True)
except actually this doesn't work:
https://github.com/pandas-dev/pandas/issues/11501
the options have been implemented for parsing, but not for displaying.
Hallo Stael/Cezar/Droravr, Thank you all for providing your inputs. I value your time and appreciate your help a lot. Thanks for sharing this link https://github.com/pandas-dev/pandas/issues/11501 as well. I went through the link and understood that this problem can be broken down to a 'displaying problem' ultimately, as also expounded by jreback. This issue to have the dates displayed to your desired format has been marked as an Enhancement, so probably will be added to future versions.
All I wanted was the have to dates exported as dd-mm-yyy and by just formatting the string while exporting, we could solve this problem.
So, I sorted this issue by exporting the file as -
dt.to_csv(filename, date_format='%d-%m-%Y',index=False).
date date_1
09.12.1998 09-12-1998
07.04.2014 07-04-2014
Thus, this issue stands SOLVED.
Once again, thank you all for your kind help and the precious hours you spent with this issue. Deeply appreciated.

Python Datetime Strptime Error: '-' is a bad directive in format '%-m-%-d-%y %-H:%M:%S'

I know that there have been similar questions asked, but they seemed to have to do with the way datetime deals (or doesn't deal) with timezones.
The setup is a little complicated, and probably not relevant to the problem, but I thought it was important to include the code as is, so a little background:
I've got a dictionary of arrays. Each of these arrays represents an "attempt" by the same person, but taking place at different times. Ultimately I'm going to be looking for the earliest of these dates. This may be a bit of a roundabout solution, but I'm converting all of the dates to datetime objects, finding the earliest and then just using that index to pull out the first attempt:
Here's what the code looks like to setup that array of attempt datetimes:
for key in duplicates_set.keys():
attempt_dates = [datetime.strptime(attempt['Attempt Date'], "%-m-%-d-%y %-H:%M:%S") for attempt in duplicates_set[key]]
Here's the format of what one of the original date strings looks like:
12-5-2016 3:27:58 PM
What I'm getting back is:
ValueError: '-' is a bad directive in format '%-m-%d-%y %-H:%M:%S'
I assume that's referring to the dashes placed before the 'm', 'd' and 'H' because they're non-zero-padded decimals. Why is it telling me that?
%-* -- to skip padding -- is a GNU libc extension. It's not part of POSIX strftime, and thus not guaranteed to be portable to systems where your time-formatting calls aren't eventually backed by GNU's strftime C library function.
The Python datetime module documentation explicitly specifies the format strings it supports, and this extension is not given. Thus, while this is supported in GNU date and GNU strftime(), it isn't available in Python datetime.
I had the same issue;
date: 1/9/21
according to:
https://strftime.org/ the correct format would've been "%-d/%-m/%y"
which gave the bad directive error.
"%d-/%m-/%y" didn't work either.
Weirdly enough what worked was "%d/%m/%y".

Efficient way for python date string manipulation

I want to turn '07/18/2013' to '07/2013' and there are a lot of these strings to be processed. What would be the most efficient way to do it?
I am thinking of using
''.join(['07/18/2013'[0:3],'07/18/2013'[6:]])
Look into strftime and strptime.
Assuming you start with the string s you can put it into a datetime object using strptime then take that back out into a string with only the necessary fields using strftime. I didn't actually run this code so I don't know if it is perfect, but the idea is here.
temp = datetime.strptime.(s, "%m/%D/%Y")
final = temp.strftime(%m/%Y")
You can find info on the datetime functions here https://docs.python.org/2/library/datetime.html
Use datetime module:
import datetime
print datetime.datetime.strptime("07/18/2013", '%m/%d/%Y').strftime('%m/%Y')

Python PIL save file with datetime as name

I'm relatively new to python and know very little syntax, but I'm willing to learn as much as possible. Simply put I want to use the save feature in PIL to save a .png with the file's name being the current date and time. This may be complicated by the fact that I'm not using PIL directly, but through the Videocapture module, but i doubt it. this is my code that works
from VideoCapture import Device
cam = Device()
cam.saveSnapshot('C:\Users\Myname\Dropbox\Foldes\image.png', timestamp=3, boldfont=1, textpos='bc')
Its short, but it does what I need it to.
I realize Datetime will need to be imported, But I can't get the data as the name without errors. yes i have tried the str() command. Any help will be greatly appreciated.
'C:\Users\Myname\Dropbox\Foldes\image.png'
In strings in Python, backslashes have special meaning so you need to treat them differently. You can either use two of them instead of one...
'C:\\Users\\Myname\\Dropbox\\Foldes\\image.png'
...or you can put an r before the string (as long as it doesn't end with a backslash)
r'C:\Users\Myname\Dropbox\Foldes\image.png'
To generate a string containing the current day in YYYY-MM-DD-HH:MM format, we can use the datetime module like this. To format the timestamp differently, consult the documentation here.
import datetime
date_string = datetime.datetime.now().strftime("%Y-%m-%d-%H:%M")
As a shorter alternative, you could use the similar time module instead:
import time
date_string = time.strftime("%Y-%m-%d-%H:%M")
After this, you should just be able to do
cam.saveSnapshot(r'C:\Users\Myname\Dropbox\Foldes\image-' + date_string + '.png',
timestamp=3, boldfont=1, textpos='bc')
to save the image with the datetime in the filename. (I have split the function call over two lines for readability, see this question for some explanation of how this works.)

Categories