If the reason you're checking is so you can do something like if file_exists: open_it(), it's safer to use a try around the attempt to open it. Checking and then opening risks the file being deleted or moved or something between when you check and when you try to open it.
If you're not planning to open the file immediately, you can use os.path.isfile
Return True if path is an existing regular file. This follows symbolic links, so both islink() and isfile() can be true for the same path.
import os.path
os.path.isfile(fname)
if you need to be sure it's a file.
Starting with Python 3.4, the pathlib module offers an object-oriented approach (backported to pathlib2 in Python 2.7):
from pathlib import Path
my_file = Path("/path/to/file")
if my_file.is_file():
# file exists
To check a directory, do:
if my_file.is_dir():
# directory exists
To check whether a Path object exists independently of whether is it a file or directory, use exists():
if my_file.exists():
# path exists
You can also use resolve(strict=True) in a try block:
try:
my_abs_path = my_file.resolve(strict=True)
except FileNotFoundError:
# doesn't exist
else:
# exists
shutil has many methods you can use. One of which is:
from shutil import copyfile
copyfile(src, dst)
# 2nd option
copy(src, dst) # dst can be a folder; use copy2() to preserve timestamp
- Copy the contents of the file named
src to a file named dst. Both src and dst need to be the entire filename of the files, including path.
- The destination location must be writable; otherwise, an
IOError exception will be raised.
- If
dst already exists, it will be replaced.
- Special files such as character or block devices and pipes cannot be copied with this function.
- With
copy, src and dst are path names given as strs.
Another shutil method to look at is shutil.copy2(). It's similar but preserves more metadata (e.g. time stamps).
If you use os.path operations, use copy rather than copyfile. copyfile will only accept strings.
Best Answer
You need to check for the parameter being blank:
if "%~1"=="" goto blankOnce you've done that, then do an if/else switch on -b:
if "%~1"=="-b" (goto specific) else goto unknownSurrounding the parameters with quotes makes checking for things like blank/empty/missing parameters easier. "~" ensures double quotes are stripped if they were on the command line argument.