How to create a file name with the current date & time in Python?

Question

Here is a functional code (create file with success)

sys.stdout = open('filename1.xml', 'w')

Now I'm trying to name the file with the current date/time (I'm not an expert in Python)

filename1 = datetime.now().strftime("%Y%m%d-%H%M%S")
sys.stdout = open(filename1 + '.xml', 'w')

I want to write out a file name with the exact date and time, it is a xml file, that the program has already create, I just need to name the file. The above code is not working.

The error returned:

  File "./fix.py", line 226, in <module>
    filenames = datetime.now().strftime("%Y%m%d-%H%M%S")
AttributeError: 'module' object has no attribute 'now'

Levon · Accepted Answer · 2012-05-15T22:22:14.407

586

While not using datetime, this solves your problem (answers your question) of getting a string with the current time and date format you specify:

import time
timestr = time.strftime("%Y%m%d-%H%M%S")
print timestr

yields:

20120515-155045

so your filename could append or use this string.

edited May 15 '12 at 22:22

answered May 15 '12 at 19:48

Levon

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Gotcha! time was not defined in my script and I was trying to use timedate (not work, I do not why), but with time it is clear now, the filename is created with success. Thank You so much! – devasia2112 May 15 '12 at 19:56
3

I don't know why you accepted this answer when there are two answers that explain perfectly well what was wrong with the code in the question. Nothing against the way Levon did this, it works fine, but when you say "not work, I don't know why", it seems odd because you have answers that explain why. – David Heffernan May 15 '12 at 19:58
When I tried the code above, I received a, "E AttributeError: 'int' object has no attribute 'strftime'" error. – rwbyrd Aug 25 '15 at 15:30
@rwbyrd That is odd, I just tried those exact 3 lines (copy-paste) with Python 3.4.1 and 2.7.6 and it works - though with Python 3 you need to use `print(timestr)`. Did you copy this text from above? Perhaps a typo otherwise? – Levon Aug 25 '15 at 15:46
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@rwbyrd You probably have an int variable called "time" somewhere in scope that is shadowing the `time` module. – Thomas Sep 20 '15 at 05:04
For the ones looking for the strftime parameters: https://docs.python.org/3/library/time.html#time.strftime – Torsten Feb 07 '23 at 10:16

score 77 · Answer 2 · answered May 15 '12 at 19:55

77

Change this line

filename1 = datetime.now().strftime("%Y%m%d-%H%M%S")

To

filename1 = datetime.datetime.now().strftime("%Y%m%d-%H%M%S")

Note the extra datetime. Alternatively, change your import datetime to from datetime import datetime

answered May 15 '12 at 19:55

Andy

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@B4NZ41 That's not true. The error message makes it clear that your code has `import datetime` somewhere. – David Heffernan May 15 '12 at 20:00
;) Sorry! NOW I'm using import time, before I was using import datetime – devasia2112 May 15 '12 at 20:04
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@B4NZ41 It doesn't matter what you are doing now. It matters what is in the question. – David Heffernan May 15 '12 at 20:07

Dev Aggarwal · Answer 3 · 2020-08-11T21:58:49.540

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This one is much more human readable.

from datetime import datetime

datetime.now().strftime("%Y_%m_%d-%I_%M_%S_%p")

'2020_08_12-03_29_22_AM'

edited Aug 11 '20 at 21:58

answered Aug 15 '19 at 18:26

Dev Aggarwal

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Yes but sorting by name will not sort chronologically – Peter Jan 31 '20 at 23:49
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I guess that just requires YYMMDD instead of DDMMYY? – Dev Aggarwal Feb 01 '20 at 11:20
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Now its fine for chronological sorting (it has been edited). – Rémy Hosseinkhan Boucher Dec 27 '22 at 17:26
that is **NOT** chronologically sorted... 4 PM shows before 5 AM... I rather use: `datetime.now().strftime("%Y_%m_%d-%p%I_%M_%S")` – BrainOverflow May 29 '23 at 12:50

David Heffernan · Answer 4 · 2012-05-15T19:59:49.327

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now is a class method in the class datetime in the module datetime. So you need

datetime.datetime.now()

Or you can use a different import

from datetime import datetime

Done this way allows you to use datetime.now as per the code in the question.

edited May 15 '12 at 19:59

answered May 15 '12 at 19:53

David Heffernan

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score 8 · Answer 5 · edited Oct 19 '21 at 12:11

8

Here's some that I needed to include the date-time stamp in the folder name for dumping files from a web scraper.

# import time and OS modules to use to build file folder name
import datetime
import time
import os

# Build string for directory to hold files
# Output Configuration
#   drive_letter = Output device location (hard drive) 
#   folder_name = directory (folder) to receive and store PDF files

drive_letter = r'D:\\' 
folder_name = r'downloaded-files'
folder_time = datetime.now().strftime("%Y-%m-%d_%I-%M-%S_%p")
folder_to_save_files = drive_letter + folder_name + folder_time 

# IF no such folder exists, create one automatically
if not os.path.exists(folder_to_save_files):
    os.mkdir(folder_to_save_files)

edited Oct 19 '21 at 12:11

Yonas Kassa

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answered Dec 26 '19 at 03:48

Rich Lysakowski PhD

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A safer way to create your path, might be: `folder_to_save_files = shutil.os.path.join(drive_letter, folder_name +folder_time)` (also an `import shutil` statement can replace the `import os` statement ) – oneindelijk Jul 06 '20 at 17:30
Thanks to yosemite_k for adding the import datetime. Yes, oneindelijk that is a safer way. – Rich Lysakowski PhD Oct 20 '21 at 03:35

score 7 · Answer 6 · edited Oct 07 '16 at 10:04

7

I'm surprised there is not some single formatter that returns a default (and safe) 'for appending in filename' - format of the time, We could simply write FD.write('mybackup'+time.strftime('%(formatter here)') + 'ext'

"%x" instead of "%Y%m%d-%H%M%S"

edited Oct 07 '16 at 10:04

J. Chomel

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answered Jan 20 '16 at 02:31

oneindelijk

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score 4 · Answer 7 · answered Feb 04 '21 at 06:46

4

This prints in an easy to read format -

import datetime

time_now  = datetime.datetime.now().strftime('%m_%d_%Y_%H_%M_%S') 

print(time_now)

Output: 02_03_2021_22_44_50

answered Feb 04 '21 at 06:46

mellifluous

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score 3 · Answer 8 · edited Feb 04 '21 at 08:21

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import datetime

def print_time():
    parser = datetime.datetime.now() 
    return parser.strftime("%d-%m-%Y %H:%M:%S")

print(print_time())

# Output>
# 03-02-2021 22:39:28

edited Feb 04 '21 at 08:21

mellifluous

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answered Dec 10 '20 at 11:57

Mario Cretoiu

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Please add ``` around your code. Like this: ``` code ``` -> `code`. Also add some explaination. – Sabito stands with Ukraine Dec 10 '20 at 11:59
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You cannot create a filename containing `:` on Windows. – sekrett Nov 18 '21 at 08:51

How to create a file name with the current date & time in Python?

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