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Rename the filename using python

I have folder where I have multiple files. Out of this files I want to rename some of them. For example: PB report December21 North.xlsb, PB report November21 North.xslb and so on. They all have a same start - PB report. I would like to change their name and leave only PB report and Month. For example PB report December.
I have tried this code:
import os
path = r'C://Users//greencolor//Desktop//Autoreport//Load_attachments//'
for filename in os.listdir(path):
if filename.startswith("PB report"):
os.rename(filename, filename[:-8])
-8 indicates that I want to split the name from the end on the 8th character
I get this error:
FileNotFoundError: [WinError 2] The system cannot find the file specified
Any suggestion?

You need the path when renaming file with os.rename:
Replace:
os.rename(filename, filename[:-8])
With:
filename_part, extension = os.path.splitext(filename)
os.rename(path+filename, path+filename_part[:-8]+extension)

The problem is likely that it cannot find the file because the directory is not specified. You need to add the path to the file name:
import os
path = r'C://Users//greencolor//Desktop//Autoreport//Load_attachments//'
for filename in os.listdir(path):
if filename.startswith("PB report"):
os.rename(os.path.join(path, filename), os.path.join(path, filename[:-8]))

This is a classic example of how working with os/os.path to manipulate paths is just not convenient. This is why pathlib exists. By treating paths as objects, rather than strings everything becomes more sensible. By using a combination of path.iterdir() and path.rename() you can achieve what you want like:
from pathlib import Path
path = Path(r'your path')
for file in path.iterdir():
if file.name.startswith("PB report"):
file.rename(file.with_stem(file.stem[:-8]))
Note that stem means the filename without the extension and that with_stem was added in Python 3.9. So for older versions you can still use with_name:
file.rename(file.with_name(file.stem[:-8] + file.suffix))
Where suffix is the extension of the file.

How can I read files with similar names on python, rename them and then work with them?

I've already posted here with the same question but I sadly I couldn't come up with a solution (even though some of you guys gave me awesome answers but most of them weren't what I was looking for), so I'll try again and this time giving more information about what I'm trying to do.
So, I'm using a program called GMAT to get some outputs (.txt files with numerical values). These outputs have different names, but because I'm using them to more than one thing I'm getting something like this:
GMATd_1.txt
GMATd_2.txt
GMATf_1.txt
GMATf_2.txt
Now, what I need to do is to use these outputs as inputs in my code. I need to work with them in other functions of my script, and since I will have a lot of these .txt files I want to rename them as I don't want to use them like './path/etc'.
So what I wanted was to write a loop that could get these files and rename them inside the script so I can use these files with the new name in other functions (outside the loop).
So instead of having to this individually:
GMATds1= './path/GMATd_1.txt'
GMATds2= './path/GMATd_2.txt'
I wanted to write a loop that would do that for me.
I've already tried using a dictionary:
import os
import fnmatch
dict = {}
for filename in os.listdir('.'):
if fnmatch.fnmatch(filename, 'thing*.txt'):
examples[filename[:6]] = filename
This does work but I can't use the dictionary key outside the loop.

If I understand correctly, you try to fetch files with similar names (at least a re-occurring pattern) and rename them. This can be accomplished with the following code:
import glob
import os
all_files = glob.glob('path/to/directory/with/files/GMAT*.txt')
for file in files:
new_path = create_new_path(file) # possibly split the file name, change directory and/or filename
os.rename(file, new_path)
The glob library allows for searching files with * wildcards and makes it hence possible to search for files with a specific pattern. It lists all the files in a certain directory (or multiple directories if you include a * wildcard as a directory). When you iterate over the files, you could either directly work with the input of the files (as you apparently intend to do) or rename them as shown in this snippet. To rename them, you would need to generate a new path - so you would have to write the create_new_path function that takes the old path and creates a new one.

Since python 3.4 you should be using the built-in pathlib package instead of os or glob.
from pathlib import Path
import shutil
for file_src in Path("path/to/files").glob("GMAT*.txt"):
file_dest = str(file_src.resolve()).replace("ds", "d_")
shutil.move(file_src, file_dest)

you can use
import os
path='.....' # path where these files are located
path1='.....' ## path where you want these files to store
i=1
for file in os.listdir(path):
if file.endswith(end='.txt'):
os.rename(path + "/" + file, path1 + "/"+str(i) + ".txt")
i+=1
it will rename all the txt file in the source folder to 1,2,3,....n.txt

How to normalize a relative path using pathlib

I'm trying to use relative paths in Python, and I want to put my csv files in a separate folder from my python code.
My python program is in the following folder:
G:\projects\code
I want to read this file which is one level up:
G:\projects\data\sales.csv
How do I specify a path using pathlib that is one level up from my current working folder? I don't want to change the current working folder.
I tried this:
from pathlib import Path
file = Path.cwd() /'..'/'data'/'sales.csv'
But now the 'file' variable equals this:
'G:/projects/code/../data/sales.csv'
I read through the docs and either it isn't explained there or I'm just missing it.

Although it's not a problem that your path includes '..' (you can still use this path to open files, etc. in Python), you can normalize the path using resolve():
from pathlib import Path
path = Path.cwd() / '..' / 'data' / 'sales.csv'
print(path) # WindowsPath('G:/projects/code/../data/sales.csv')
print(path.resolve()) # WindowsPath('G:/projects/data/sales.csv')
NB: I personally would name a variable that contains a path path, not file. So you could later on do file = open(path).

print(
Path(__file__).parent, # the folder
Path(__file__).parent.parent, # the folder's parent
sep='\n'
)
print(
Path(
Path(__file__).parent.parent, 'hello.py'
)
)
results in
C:\Users\isik\Desktop\Python\MessAround\project\module
C:\Users\isik\Desktop\Python\MessAround\project
C:\Users\isik\Desktop\Python\MessAround\project\hello.py
with this file structure
-project
-module
-__init__.py
-hello.py
-__init__.py
while the code is located inside project.module.__init__.py

Do you mean "read my csv files"?
The import keyword has a different meaning in Python (you import only other Python modules).
In any case, in order to read a file located one folder above your Python file, you can use this:
import os
filePath = os.path.dirname(__file__)+'/../'+fileName
fileDesc = open(filePath)
fileData = fileDesc.read()
fileDesc.close()
...

here is an example I used:
import json
from pathlib import Path
def read_files(folder_name, file_name):
base_path = Path.cwd().joinpath('configs','resources')
path = base_path.joinpath(folder_name,file_name)
open_file = open(path,'r')
return json.load(open_file.read())

This is pretty old, but I happened on it looking for something else.
Oddly you never got a direct, obvious, answer -- you want the parent property:
from pathlib import Path
file = Path.cwd().parent / 'data' / 'sales.csv'
Note that some of the answers that say you want __file__ rather than the current working directory may be correct (depending on your use case), in which case it's:
from pathlib import Path
file = Path(__file__).parent.parent / 'data' / 'sales.csv'
(parent of the python file is the code dir, parent of that is the projects dir.
However, It's not great practice to refer to your data by its relative path to your code -- I think using the cwd is a better option -- though what you should do is pass the path to the data in to the script via sys.argv.

Rename Single .txt File In Multiple Subdirectories

I have ~60 subdirectories in a single directory. Each of these contain thousands of files, but they all contain a file named test_all_results.txt.
What I would like to do is to rename each test_all_results.txt file so that it now has the name:
foldername_all_results.txt
What is the best way to do this?

Easily accomplished using Python os interface.
Assuming you are currently in the main directory:
import os
#get a list of all sub directories
subdir = os.listdir()
for dir in subdir:
if os.path.isdir(dir): #check if directory
os.chdir(dir) #move to sub directory
os.rename('test_all_results.txt', 'foldername_all_results.txt')
os.chdir('..') #return to main directory

Using python in Linux, make this:
import os
os.system("mv old_name.txt new_name.txt")
You can automatize with a loop, renaming all filenames.

You can do:
(change your code accordingly)
import os
# current directory is the target
direct = "."
for path, dirs, files in os.walk(direct):
for f in files:
if os.path.splitext(f)[0] == "test_all_results.txt":
os.rename(os.path.join(path, f), os.path.join(path, "foldername_all_results.txt"))

There's an answer that tells you to use the os.system() method, if you do decide to call Linux commands from Python, I'd advise that you use the subprocess module instead.
Here's how you'd run the mv command with two arguments using subprocess.call:
import subprocess
subprocess.call(["mv", "filename.txt", "new-name.txt"])
INFO: here's an old (but relevant) article that explains why it's dangerous to use these methods.
Good luck.

how to get name of a file in directory using python

There is an mkv file in a folder named "export". What I want to do is to make a python script which fetches the file name from that export folder.
Let's say the folder is at "C:\Users\UserName\Desktop\New_folder\export".
How do I fetch the name?
I tried using this os.path.basename and os.path.splitext .. well.. didn't work out like I expected.

os.path implements some useful functions on pathnames. But it doesn't have access to the contents of the path. For that purpose, you can use os.listdir.
The following command will give you a list of the contents of the given path:
os.listdir("C:\Users\UserName\Desktop\New_folder\export")
Now, if you just want .mkv files you can use fnmatch(This module provides support for Unix shell-style wildcards) module to get your expected file names:
import fnmatch
import os
print([f for f in os.listdir("C:\Users\UserName\Desktop\New_folder\export") if fnmatch.fnmatch(f, '*.mkv')])
Also as #Padraic Cunningham mentioned as a more pythonic way for dealing with file names you can use glob module :
map(path.basename,glob.iglob(pth+"*.mkv"))

You can use glob:
from glob import glob
pth ="C:/Users/UserName/Desktop/New_folder/export/"
print(glob(pth+"*.mkv"))
path+"*.mkv" will match all the files ending with .mkv.
To just get the basenames you can use map or a list comp with iglob:
from glob import iglob
print(list(map(path.basename,iglob(pth+"*.mkv"))))
print([path.basename(f) for f in iglob(pth+"*.mkv")])
iglob returns an iterator so you don't build a list for no reason.

I assume you're basically asking how to list files in a given directory. What you want is:
import os
print os.listdir("""C:\Users\UserName\Desktop\New_folder\export""")
If there's multiple files and you want the one(s) that have a .mkv end you could do:
import os
files = os.listdir("""C:\Users\UserName\Desktop\New_folder\export""")
mkv_files = [_ for _ in files if _[-4:] == ".mkv"]
print mkv_files

If you are searching for recursive folder search, this method will help you to get filename using os.walk, also you can get those file's path and directory using this below code.
import os, fnmatch
for path, dirs, files in os.walk(os.path.abspath(r"C:/Users/UserName/Desktop/New_folder/export/")):
for filename in fnmatch.filter(files, "*.mkv"):
print(filename)

You can use glob
import glob
for file in glob.glob('C:\Users\UserName\Desktop\New_folder\export\*.mkv'):
print(str(file).split('\')[-1])
This will list out all the files having extention .mkv as
file.mkv, file2.mkv and so on.

From os.walk you can read file paths as a list
files = [ file_path for _, _, file_path in os.walk(DIRECTORY_PATH)]
for file_name in files[0]: #note that it has list of lists
print(file_name)