Python file copying deletes original file - python

I've got the program below which runs via cron and backs up asterisk call recordings.
It works fine for the most part, however if a call is in progress at the time then the act of trying to copy it seems to kill it, i.e. it disappears from both the source and destination.
Is there any way to prevent this, i.e. could I test if a file is in use somehow before trying to copy it?
Thanks
from datetime import datetime
from glob import iglob
from os.path import basename, dirname, isdir
from os import makedirs
from sys import argv
from shutil import copyfile
def copy_asterisk_files_tree(src, fullpath=None):
DEST = datetime.now().strftime('/mnt/shardik/asteriskcalls/' + src)
if fullpath is None:
fullpath = src
if not isdir(DEST):
makedirs(DEST)
for path in iglob(src + '/*'):
if isdir(path):
copy_asterisk_files_tree(path, fullpath)
else:
subdir = '%s/%s' % (
DEST, dirname(path)[len(fullpath) + 1:]
)
if not isdir(subdir):
makedirs(subdir)
copyfile(path, '%s/%s' % (
subdir, basename(path).replace(':', '-')
))
if __name__ == '__main__':
if len(argv) != 2:
print 'You must specify the source path as the first argument!'
exit(1)
copy_asterisk_files_tree(argv[1])

What you need to do is use a lock. Take a look at the docs ...
https://docs.python.org/2/library/fcntl.html#fcntl.flock
fcntl.flock(fd, op)
Perform the lock operation op on file descriptor fd (file objects
providing a fileno() method are accepted as well). See the Unix manual
flock(2) for details. (On some systems, this function is emulated
using fcntl().)
This has also been answered on SO in previous questions, such as this one: Locking a file in Python, which uses filelock (https://pypi.python.org/pypi/filelock/). Filelock is platform independant.
You could also write to a temporary file/s and merge them, but I'd much prefer

Related

How to suppress a folder or a file with os module [duplicate]

How can I delete a file or folder?
os.remove() removes a file.
os.rmdir() removes an empty directory.
shutil.rmtree() deletes a directory and all its contents.
Path objects from the Python 3.4+ pathlib module also expose these instance methods:
pathlib.Path.unlink() removes a file or symbolic link.
pathlib.Path.rmdir() removes an empty directory.
Python syntax to delete a file
import os
os.remove("/tmp/<file_name>.txt")
or
import os
os.unlink("/tmp/<file_name>.txt")
or
pathlib Library for Python version >= 3.4
file_to_rem = pathlib.Path("/tmp/<file_name>.txt")
file_to_rem.unlink()
Path.unlink(missing_ok=False)
Unlink method used to remove the file or the symbolik link.
If missing_ok is false (the default), FileNotFoundError is raised if the path does not exist.
If missing_ok is true, FileNotFoundError exceptions will be ignored (same behavior as the POSIX rm -f command).
Changed in version 3.8: The missing_ok parameter was added.
Best practice
First, check if the file or folder exists and then delete it. You can achieve this in two ways:
os.path.isfile("/path/to/file")
Use exception handling.
EXAMPLE for os.path.isfile
#!/usr/bin/python
import os
myfile = "/tmp/foo.txt"
# If file exists, delete it.
if os.path.isfile(myfile):
os.remove(myfile)
else:
# If it fails, inform the user.
print("Error: %s file not found" % myfile)
Exception Handling
#!/usr/bin/python
import os
# Get input.
myfile = raw_input("Enter file name to delete: ")
# Try to delete the file.
try:
os.remove(myfile)
except OSError as e:
# If it fails, inform the user.
print("Error: %s - %s." % (e.filename, e.strerror))
Respective output
Enter file name to delete : demo.txt
Error: demo.txt - No such file or directory.
Enter file name to delete : rrr.txt
Error: rrr.txt - Operation not permitted.
Enter file name to delete : foo.txt
Python syntax to delete a folder
shutil.rmtree()
Example for shutil.rmtree()
#!/usr/bin/python
import os
import sys
import shutil
# Get directory name
mydir = raw_input("Enter directory name: ")
# Try to remove the tree; if it fails, throw an error using try...except.
try:
shutil.rmtree(mydir)
except OSError as e:
print("Error: %s - %s." % (e.filename, e.strerror))
Use
shutil.rmtree(path[, ignore_errors[, onerror]])
(See complete documentation on shutil) and/or
os.remove
and
os.rmdir
(Complete documentation on os.)
Here is a robust function that uses both os.remove and shutil.rmtree:
def remove(path):
""" param <path> could either be relative or absolute. """
if os.path.isfile(path) or os.path.islink(path):
os.remove(path) # remove the file
elif os.path.isdir(path):
shutil.rmtree(path) # remove dir and all contains
else:
raise ValueError("file {} is not a file or dir.".format(path))
You can use the built-in pathlib module (requires Python 3.4+, but there are backports for older versions on PyPI: pathlib, pathlib2).
To remove a file there is the unlink method:
import pathlib
path = pathlib.Path(name_of_file)
path.unlink()
Or the rmdir method to remove an empty folder:
import pathlib
path = pathlib.Path(name_of_folder)
path.rmdir()
Deleting a file or folder in Python
There are multiple ways to Delete a File in Python but the best ways are the following:
os.remove() removes a file.
os.unlink() removes a file. it is a Unix name of remove() method.
shutil.rmtree() deletes a directory and all its contents.
pathlib.Path.unlink() deletes a single file The pathlib module is available in Python 3.4 and above.
os.remove()
Example 1: Basic Example to Remove a File Using os.remove() Method.
import os
os.remove("test_file.txt")
print("File removed successfully")
Example 2: Checking if File Exists using os.path.isfile and Deleting it With os.remove
import os
#checking if file exist or not
if(os.path.isfile("test.txt")):
#os.remove() function to remove the file
os.remove("test.txt")
#Printing the confirmation message of deletion
print("File Deleted successfully")
else:
print("File does not exist")
#Showing the message instead of throwig an error
Example 3: Python Program to Delete all files with a specific extension
import os
from os import listdir
my_path = 'C:\Python Pool\Test\'
for file_name in listdir(my_path):
if file_name.endswith('.txt'):
os.remove(my_path + file_name)
Example 4: Python Program to Delete All Files Inside a Folder
To delete all files inside a particular directory, you simply have to use the * symbol as the pattern string.
#Importing os and glob modules
import os, glob
#Loop Through the folder projects all files and deleting them one by one
for file in glob.glob("pythonpool/*"):
os.remove(file)
print("Deleted " + str(file))
os.unlink()
os.unlink() is an alias or another name of os.remove() . As in the Unix OS remove is also known as unlink.
Note: All the functionalities and syntax is the same of os.unlink() and os.remove(). Both of them are used to delete the Python file path.
Both are methods in the os module in Python’s standard libraries which performs the deletion function.
shutil.rmtree()
Example 1: Python Program to Delete a File Using shutil.rmtree()
import shutil
import os
# location
location = "E:/Projects/PythonPool/"
# directory
dir = "Test"
# path
path = os.path.join(location, dir)
# removing directory
shutil.rmtree(path)
Example 2: Python Program to Delete a File Using shutil.rmtree()
import shutil
import os
location = "E:/Projects/PythonPool/"
dir = "Test"
path = os.path.join(location, dir)
shutil.rmtree(path)
pathlib.Path.rmdir() to remove Empty Directory
Pathlib module provides different ways to interact with your files. Rmdir is one of the path functions which allows you to delete an empty folder. Firstly, you need to select the Path() for the directory, and then calling rmdir() method will check the folder size. If it’s empty, it’ll delete it.
This is a good way to deleting empty folders without any fear of losing actual data.
from pathlib import Path
q = Path('foldername')
q.rmdir()
How do I delete a file or folder in Python?
For Python 3, to remove the file and directory individually, use the unlink and rmdir Path object methods respectively:
from pathlib import Path
dir_path = Path.home() / 'directory'
file_path = dir_path / 'file'
file_path.unlink() # remove file
dir_path.rmdir() # remove directory
Note that you can also use relative paths with Path objects, and you can check your current working directory with Path.cwd.
For removing individual files and directories in Python 2, see the section so labeled below.
To remove a directory with contents, use shutil.rmtree, and note that this is available in Python 2 and 3:
from shutil import rmtree
rmtree(dir_path)
Demonstration
New in Python 3.4 is the Path object.
Let's use one to create a directory and file to demonstrate usage. Note that we use the / to join the parts of the path, this works around issues between operating systems and issues from using backslashes on Windows (where you'd need to either double up your backslashes like \\ or use raw strings, like r"foo\bar"):
from pathlib import Path
# .home() is new in 3.5, otherwise use os.path.expanduser('~')
directory_path = Path.home() / 'directory'
directory_path.mkdir()
file_path = directory_path / 'file'
file_path.touch()
and now:
>>> file_path.is_file()
True
Now let's delete them. First the file:
>>> file_path.unlink() # remove file
>>> file_path.is_file()
False
>>> file_path.exists()
False
We can use globbing to remove multiple files - first let's create a few files for this:
>>> (directory_path / 'foo.my').touch()
>>> (directory_path / 'bar.my').touch()
Then just iterate over the glob pattern:
>>> for each_file_path in directory_path.glob('*.my'):
... print(f'removing {each_file_path}')
... each_file_path.unlink()
...
removing ~/directory/foo.my
removing ~/directory/bar.my
Now, demonstrating removing the directory:
>>> directory_path.rmdir() # remove directory
>>> directory_path.is_dir()
False
>>> directory_path.exists()
False
What if we want to remove a directory and everything in it?
For this use-case, use shutil.rmtree
Let's recreate our directory and file:
file_path.parent.mkdir()
file_path.touch()
and note that rmdir fails unless it's empty, which is why rmtree is so convenient:
>>> directory_path.rmdir()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "~/anaconda3/lib/python3.6/pathlib.py", line 1270, in rmdir
self._accessor.rmdir(self)
File "~/anaconda3/lib/python3.6/pathlib.py", line 387, in wrapped
return strfunc(str(pathobj), *args)
OSError: [Errno 39] Directory not empty: '/home/username/directory'
Now, import rmtree and pass the directory to the funtion:
from shutil import rmtree
rmtree(directory_path) # remove everything
and we can see the whole thing has been removed:
>>> directory_path.exists()
False
Python 2
If you're on Python 2, there's a backport of the pathlib module called pathlib2, which can be installed with pip:
$ pip install pathlib2
And then you can alias the library to pathlib
import pathlib2 as pathlib
Or just directly import the Path object (as demonstrated here):
from pathlib2 import Path
If that's too much, you can remove files with os.remove or os.unlink
from os import unlink, remove
from os.path import join, expanduser
remove(join(expanduser('~'), 'directory/file'))
or
unlink(join(expanduser('~'), 'directory/file'))
and you can remove directories with os.rmdir:
from os import rmdir
rmdir(join(expanduser('~'), 'directory'))
Note that there is also a os.removedirs - it only removes empty directories recursively, but it may suit your use-case.
This is my function for deleting dirs. The "path" requires the full pathname.
import os
def rm_dir(path):
cwd = os.getcwd()
if not os.path.exists(os.path.join(cwd, path)):
return False
os.chdir(os.path.join(cwd, path))
for file in os.listdir():
print("file = " + file)
os.remove(file)
print(cwd)
os.chdir(cwd)
os.rmdir(os.path.join(cwd, path))
shutil.rmtree is the asynchronous function,
so if you want to check when it complete, you can use while...loop
import os
import shutil
shutil.rmtree(path)
while os.path.exists(path):
pass
print('done')
import os
folder = '/Path/to/yourDir/'
fileList = os.listdir(folder)
for f in fileList:
filePath = folder + '/'+f
if os.path.isfile(filePath):
os.remove(filePath)
elif os.path.isdir(filePath):
newFileList = os.listdir(filePath)
for f1 in newFileList:
insideFilePath = filePath + '/' + f1
if os.path.isfile(insideFilePath):
os.remove(insideFilePath)
For deleting files:
os.unlink(path, *, dir_fd=None)
or
os.remove(path, *, dir_fd=None)
Both functions are semantically same. This functions removes (deletes) the file path. If path is not a file and it is directory, then exception is raised.
For deleting folders:
shutil.rmtree(path, ignore_errors=False, onerror=None)
or
os.rmdir(path, *, dir_fd=None)
In order to remove whole directory trees, shutil.rmtree() can be used. os.rmdir only works when the directory is empty and exists.
For deleting folders recursively towards parent:
os.removedirs(name)
It remove every empty parent directory with self until parent which has some content
ex. os.removedirs('abc/xyz/pqr') will remove the directories by order 'abc/xyz/pqr', 'abc/xyz' and 'abc' if they are empty.
For more info check official doc: os.unlink , os.remove, os.rmdir , shutil.rmtree, os.removedirs
To remove all files in folder
import os
import glob
files = glob.glob(os.path.join('path/to/folder/*'))
files = glob.glob(os.path.join('path/to/folder/*.csv')) // It will give all csv files in folder
for file in files:
os.remove(file)
To remove all folders in a directory
from shutil import rmtree
import os
// os.path.join() # current working directory.
for dirct in os.listdir(os.path.join('path/to/folder')):
rmtree(os.path.join('path/to/folder',dirct))
To avoid the TOCTOU issue highlighted by Éric Araujo's comment, you can catch an exception to call the correct method:
def remove_file_or_dir(path: str) -> None:
""" Remove a file or directory """
try:
shutil.rmtree(path)
except NotADirectoryError:
os.remove(path)
Since shutil.rmtree() will only remove directories and os.remove() or os.unlink() will only remove files.
My personal preference is to work with pathlib objects - it offers a more pythonic and less error-prone way to interact with the filesystem, especially if You develop cross-platform code.
In that case, You might use pathlib3x - it offers a backport of the latest (at the date of writing this answer Python 3.10.a0) Python pathlib for Python 3.6 or newer, and a few additional functions like "copy", "copy2", "copytree", "rmtree" etc ...
It also wraps shutil.rmtree:
$> python -m pip install pathlib3x
$> python
>>> import pathlib3x as pathlib
# delete a directory tree
>>> my_dir_to_delete=pathlib.Path('c:/temp/some_dir')
>>> my_dir_to_delete.rmtree(ignore_errors=True)
# delete a file
>>> my_file_to_delete=pathlib.Path('c:/temp/some_file.txt')
>>> my_file_to_delete.unlink(missing_ok=True)
you can find it on github or PyPi
Disclaimer: I'm the author of the pathlib3x library.
I recommend using subprocess if writing a beautiful and readable code is your cup of tea:
import subprocess
subprocess.Popen("rm -r my_dir", shell=True)
And if you are not a software engineer, then maybe consider using Jupyter; you can simply type bash commands:
!rm -r my_dir
Traditionally, you use shutil:
import shutil
shutil.rmtree(my_dir)

Renaming log files with Python using wildcard and datetime

I was searching today for options to manipulate some log files, after executing actions on them, and I found that Python has the os.rename resource, after importing the os module, but I have some regex doubts..
Tried to fit a wildcard "*****" on my file names, but Python seems not to understand it.
My file names are:
Application_2021-08-06_hostname_[PID].log
Currently I'm asking Python to read these application files, and search for defined words/phrases such as "User has logged in", "User disconnected" and etc. And he does well. I'm using datetime module so Python will always read the current files only.
But what I'm trying to do now, is to change the name of the file, after Python read it and execute something. So when he find "Today's sessions are done", he will change the name of the file to:
Application_06-08-2021_hostname_[PID].log
Because it will be easier for manipulating later..
Considering that [PID] will always change, this is the part that I wanted to set the wildcard, because it can be 56, 142, 3356, 74567 or anything.
Using the os.rename module, I've got some errors. What do you suggest?
Code:
import os
import time
from datetime import datetime
path = '/users/application/logs'
file_name = 'Application_%s_hostname_'% datetime.now().strftime('%Y-%m-%d')
new_file_name = 'Application_%s_hostname_'% datetime.now().strftime('%d-%m-%Y')
os.rename(file_name, new_file_name)
The error is:
OSError: [Errno 2] No such file or directory
You can use glob which allows for wildcards:
import glob, os
from datetime import datetime
current_date = datetime.now()
path = '/users/application/logs'
# note the use of * as wild card
filename ='Application_%s_hostname_*'% current_date.strftime('%Y-%m-%d')
full_path = os.path.join(path, filename)
replace_file = glob.glob(full_path)[0] # will return a list so take first element
# or loop to get all files
new_name = replace_file.replace( current_date.strftime('%Y-%m-%d'), current_date.strftime('%d-%m-%Y') )
os.rename(replace_file, new_name)

Moving all contents of a directory to another in Python

I've been trying to figure this out for hours with no luck. I have a list of directories that have subdirectories and other files of their own. I'm trying to traverse through all of them and move all of their content to a specific location. I tried shutil and glob but I couldn't get it to work. I even tried to run shell commands using subprocess.call and that also did not work either. I understand that it didn't work because I couldn't apply it properly but I couldn't find any solution that moves all contents of a directory to another.
files = glob.glob('Food101-AB/*/')
dest = 'Food-101/'
if not os.path.exists(dest):
os.makedirs(dest)
subprocess.call("mv Food101-AB/* Food-101/", shell=True)
# for child in files:
# shutil.move(child, dest)
I'm trying to move everything in Food101-AB to Food-101
shutil module of the standart library is the way to go:
>>> import shutil
>>> shutil.move("Food101-AB", "Food-101")
If you don't want to move Food101-AB folder itself, try using this:
import shutil
import os
for i in os.listdir("Food101-AB"):
shutil.move(os.path.join("Food101-AB", i), "Food-101")
For more information about move function:
https://docs.python.org/3/library/shutil.html#shutil.move
Try to change call function to run in order to retrieve the stdout, stderr and return code for your shell command:
from subprocess import run, CalledProcessError
source_dir = "full/path/to/src/folder"
dest_dir = "full/path/to/dest/folder"
try:
res = run(["mv", source_dir, dest_dir], check=True, capture_output=True)
except CalledProcessError as ex:
print(ex.stdout, ex.stderr, ex.returncode)

Creating Modules and using them

I am playing around with creating modules.I have two python scripts.The first (the module) has:
def abspath(relpath):
import os
absdir = os.path.realpath('__file__')
absdir = absdir.split('_')[0].replace('\\', '/')
filename = str(absdir + relpath )
print (filename)
return filename;
The second file (main) has:
import file_tools as ft
filename = ft.abspath('some/path/')
When I run Main, filename appears empty (Type:None). I have run the filename = abspath(etc) within the 'module', and it works. Clearly, I am missing something here!!
and doing this, so any help would be useful.
Thank's all.
MT
The problem lies in how you're finding the working directory; the preferred method being os.getcwd() (or os.getcwdb for Unix compatibility). Using that, we can see that your function boils down to:
def abspath(relpath):
return os.path.join(os.getcwd(), relpath)

Build the full path filename in Python

I need to pass a file path name to a module. How do I build the file path from a directory name, base filename, and a file format string?
The directory may or may not exist at the time of call.
For example:
dir_name='/home/me/dev/my_reports'
base_filename='daily_report'
format = 'pdf'
I need to create a string '/home/me/dev/my_reports/daily_report.pdf'
Concatenating the pieces manually doesn't seem to be a good way. I tried os.path.join:
join(dir_name,base_filename,format)
but it gives
/home/me/dev/my_reports/daily_report/pdf
This works fine:
os.path.join(dir_name, base_filename + '.' + filename_suffix)
Keep in mind that os.path.join() exists only because different operating systems use different path separator characters. It smooths over that difference so cross-platform code doesn't have to be cluttered with special cases for each OS. There is no need to do this for file name "extensions" (see footnote) because they are always preceded by a dot character, on every OS.
If using a function anyway makes you feel better (and you like needlessly complicating your code), you can do this:
os.path.join(dir_name, '.'.join((base_filename, filename_suffix)))
If you prefer to keep your code clean, simply include the dot in the suffix:
suffix = '.pdf'
os.path.join(dir_name, base_filename + suffix)
That approach also happens to be compatible with the suffix conventions in pathlib, which was introduced in python 3.4 a few years after this question was asked. New code that doesn't require backward compatibility can do this:
suffix = '.pdf'
pathlib.PurePath(dir_name, base_filename + suffix)
You might be tempted to use the shorter Path() instead of PurePath() if you're only handling paths for the local OS. I would question that choice, given the cross-platform issues behind the original question.
Warning: Do not use pathlib's with_suffix() for this purpose. That method will corrupt base_filename if it ever contains a dot.
Footnote: Outside of Microsoft operating systems, there is no such thing as a file name "extension". Its presence on Windows comes from MS-DOS and FAT, which borrowed it from CP/M, which has been dead for decades. That dot-plus-three-letters that many of us are accustomed to seeing is just part of the file name on every other modern OS, where it has no built-in meaning.
If you are fortunate enough to be running Python 3.4+, you can use pathlib:
>>> from pathlib import Path
>>> dirname = '/home/reports'
>>> filename = 'daily'
>>> suffix = '.pdf'
>>> Path(dirname, filename).with_suffix(suffix)
PosixPath('/home/reports/daily.pdf')
Um, why not just:
>>> import os
>>> os.path.join(dir_name, base_filename + "." + format)
'/home/me/dev/my_reports/daily_report.pdf'
Is not it better to add the format in the base filename?
dir_name='/home/me/dev/my_reports/'
base_filename='daily_report.pdf'
os.path.join(dir_name, base_filename)
Just use os.path.join to join your path with the filename and extension. Use sys.argv to access arguments passed to the script when executing it:
#!/usr/bin/env python3
# coding: utf-8
# import netCDF4 as nc
import numpy as np
import numpy.ma as ma
import csv as csv
import os.path
import sys
basedir = '/data/reu_data/soil_moisture/'
suffix = 'nc'
def read_fid(filename):
fid = nc.MFDataset(filename,'r')
fid.close()
return fid
def read_var(file, varname):
fid = nc.Dataset(file, 'r')
out = fid.variables[varname][:]
fid.close()
return out
if __name__ == '__main__':
if len(sys.argv) < 2:
print('Please specify a year')
else:
filename = os.path.join(basedir, '.'.join((sys.argv[1], suffix)))
time = read_var(ncf, 'time')
lat = read_var(ncf, 'lat')
lon = read_var(ncf, 'lon')
soil = read_var(ncf, 'soilw')
Simply run the script like:
# on windows-based systems
python script.py year
# on unix-based systems
./script.py year
from pathlib import Path
# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent
TEMPLATE_PATH = Path.joinpath(BASE_DIR,"templates")
print(TEMPLATE_PATH)
Adding code below for better understanding:
import os
def createfile(name, location, extension):
print(name, extension, location)
#starting creating a file with some dummy contents
path = os.path.join(location, name + '.' + extension)
f = open(path, "a")
f.write("Your contents!! or whatever you want to put inside this file.")
f.close()
print("File creation is successful!!")
def readfile(name, location, extension):
#open and read the file after the appending:
path = os.path.join(location, name + '.' + extension)
f = open(path, "r")
print(f.read())
#pass the parameters here
createfile('test','./','txt')
readfile('test','./','txt')

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