Adding timestamp to a file in PYTHON - python-3.x

Question

I can able to rename a file without any problem/error using os.rename().
But the moment I tried to rename a file with timestamp adding to it, it throws win3 error or win123 error, tried all combinations but no luck, Could anyone help.
Successfully Ran Code :
#!/usr/bin/python
import datetime
import os
import shutil
import json
import re
maindir = "F:/Protocols/"
os.chdir(maindir)
maindir = os.getcwd()
print("Working Directory : "+maindir)
path_4_all_iter = os.path.abspath("all_iteration.txt")
now = datetime.datetime.now()
timestamp = str(now.strftime("%Y%m%d_%H:%M:%S"))
print(type(timestamp))
archive_name = "all_iteration_"+timestamp+".txt"
print(archive_name)
print(os.getcwd())
if os.path.exists("all_iteration.txt"):
print("File Exists")
os.rename(path_4_all_iter, "F:/Protocols/archive/archive.txt")
print(os.listdir("F:/Protocols/archive/"))
print(os.path.abspath("all_iteration.txt"))
Log :
E:\python.exe C:/Users/SPAR/PycharmProjects/Sample/debug.py
Working Directory : F:\Protocols
<class 'str'>
all_iteration_20180409_20:25:51.txt
F:\Protocols
File Exists
['archive.txt']
F:\Protocols\all_iteration.txt
Process finished with exit code 0
Error Code :
print(os.getcwd())
if os.path.exists("all_iteration.txt"):
print("File Exists")
os.rename(path_4_all_iter, "F:/Protocols/archive/"+archive_name)
print(os.listdir("F:/Protocols/archive/"))
print(os.path.abspath("all_iteration.txt"))
Error LOG:
E:\python.exe C:/Users/SPAR/PycharmProjects/Sample/debug.py
Traceback (most recent call last):
Working Directory : F:\Protocols
<class 'str'>
File "C:/Users/SPAR/PycharmProjects/Sample/debug.py", line 22, in <module>
all_iteration_20180409_20:31:16.txt
F:\Protocols
os.rename(path_4_all_iter, "F:/Protocols/archive/"+archive_name)
File Exists
OSError: [WinError 123] The filename, directory name, or volume label syntax is incorrect: 'F:\\Protocols\\all_iteration.txt' -> 'F:/Protocols/archive/all_iteration_20180409_20:31:16.txt'
Process finished with exit code 1

Answer 1

Your timestamp format has colons in it, which are not allowed in Windows filenames. See this answer on that subject:
How to get a file in Windows with a colon in the filename?
If you change your timestamp format to something like:
timestamp = str(now.strftime("%Y%m%d_%H-%M-%S"))
it should work.

Answer 2

You can't have : characters as part of the filename, so change
timestamp = str(now.strftime("%Y%m%d_%H:%M:%S"))
to
timestamp = str(now.strftime("%Y%m%d_%H%M%S"))
and you'll be able to rename your file.