If I use the following line:
shutil.copyfile(r\"\\\\mynetworkshare\\myfile.txt\",\"C:\\TEMP\\myfile.txt\")
everything works fine. However, what
The r is for "raw string", not for relative. When you don't prefix your string with r, Python will treat the backslash "\" as an escape character.
So when your string contains backslashes, you either have to put an r before it, or put two backslashes for each single one you want to appear.
>>> r"\\myfile" == "\\\\myfile"
True