Develop Reference

Altering Windows file paths so that they use '/' instead of '\' [duplicate]

I am working in python and I need to convert this:
C:\folderA\folderB to C:/folderA/folderB
I have three approaches:
dir = s.replace('\\','/')
dir = os.path.normpath(s)
dir = os.path.normcase(s)
In each scenario the output has been
C:folderAfolderB
I'm not sure what I am doing wrong, any suggestions?

I recently found this and thought worth sharing:
import os
path = "C:\\temp\myFolder\example\\"
newPath = path.replace(os.sep, '/')
print(newPath) # -> C:/temp/myFolder/example/

Your specific problem is the order and escaping of your replace arguments, should be
s.replace('\\', '/')
Then there's:
posixpath.join(*s.split('\\'))
Which on a *nix platform is equivalent to:
os.path.join(*s.split('\\'))
But don't rely on that on Windows because it will prefer the platform-specific separator. Also:
Note that on Windows, since there is a current directory for each
drive, os.path.join("c:", "foo") represents a path relative to the
current directory on drive C: (c:foo), not c:\foo.

Try
path = '/'.join(path.split('\\'))

Path names are formatted differently in Windows. the solution is simple, suppose you have a path string like this:
data_file = "/Users/username/Downloads/PMLSdata/series.csv"
simply you have to change it to this: (adding r front of the path)
data_file = r"/Users/username/Downloads/PMLSdata/series.csv"
The modifier r before the string tells Python that this is a raw string. In raw strings, the backslash is interpreted literally, not as an escape character.

Sorry for being late to the party, but I wonder no one has suggested the pathlib-library.
pathlib is a module for "Object-oriented filesystem paths"
To convert from windows-style (backslash)-paths to forward-slashes (as typically for Posix-Paths) you can do so in a very verbose (AND platform-independant) fashion with pathlib:
import pathlib
pathlib.PureWindowsPath(r"C:\folderA\folderB").as_posix()
>>> 'C:/folderA/folderB'
Be aware that the example uses the string-literal "r" (to avoid having "\" as escape-char)
In other cases the path should be quoted properly (with double backslashes) "C:\\folderA\\folderB"

To define the path's variable you have to add r initially, then add the replace statement .replace('\\', '/') at the end.
for example:
In>> path2 = r'C:\Users\User\Documents\Project\Em2Lph\'.replace('\\', '/')
In>> path2
Out>> 'C:/Users/User/Documents/Project/Em2Lph/'
This solution requires no additional libraries

How about :
import ntpath
import posixpath
.
.
.
dir = posixpath.join(*ntpath.split(s))
.
.

This can work also:
def slash_changer(directory):
if "\\" in directory:
return directory.replace(os.sep, '/')
else:
return directory
print(slash_changer(os.getcwd()))

this is the perfect solution put the letter 'r' before the string that you want to convert to avoid all special characters likes '\t' and '\f'...
like the example below:
str= r"\test\hhd"
print("windows path:",str.replace("\\","\\\\"))
print("Linux path:",str.replace("\\","/"))
result:
windows path: \\test\\hhd
Linux path: /test/hhd

Can't replace character "\"

I've been working on a program that reads out an specific PDF and converts the data to an Excel file. The program itself already works, but while trying to refine some aspects I ran into a problem. What happens is the modules I'm working with read directories with simple slashes dividing each folder, such as:
"C:/Users/UserX"
While windows directories are divided by backslashes, such as:
"C:\Users\UserX"
I thought using a simple replace would work just fine:
directory.replace("\" ,"/")
But whenever I try to run the program, the \ isn't identified as a string. Instead it pops up as orange in the IDE I'm working with (PyCharm). Is there anyway to remediate this? Or maybe another useful solution?

In general you should work with the os.path package here.
os.getcwd() gives you the current directory, you can add a subfolder of it via more arguments, and put the filename last.
import os
path_to_file = os.path.join(os.getcwd(), "childFolder", filename)

In Python, the '\' character is represented by '\\':
directory.replace("\\" ,"/")

Just try adding another backslash.
First of all you need to pass "C:\Users\UserX" as a raw string. Use
directory=r"C:\Users\UserX"
Secondly, suppress the backslash using a second backslash.
directory.replace("\\" ,"/")
All of this is required as in python the backslash (\) is a special character known as an escape character.

Try this:
import os
path = "C:\\temp\myFolder\example\\"
newPath = path.replace(os.sep, '/')
print(newPath)
Output:<< C:/temp/myFolder/example/ >>

How to enter a long and not-a-string data into the argument?

I have a problem with Python and need your help.
Take a look at this code:
import os
os.chdir('''C:\\Users\\Admin\\Desktop\\Automate_the_Boring_Stuff_onlimematerials_v.2\\automate_online-materials\\example.xlsx''')
The os.chdir() did not work because the directory I put in between the ''' and ''' is considered as raw string. Note that a line is no more than 125 characters, so I have to make a new line.
So how can I fix this?

You can split your statement into multiple lines by using the backslash \ to indicate that a statement is continued on the new line.
message = 'This message will not generate an error because \
it was split by using the backslash on your \
keyboard'
print(message)
Output
This message will not generate an error because it was split by using the backslash on your keyboard

Lines can be longer than 125 characters, but you should probably avoid that. You have a few solutions:
x = ('hi'
'there')
# x is now the string "hithere"
os.chdir('hi'
'there') # does a similar thing (os.chdir('hithere'))
You could also set up a variable:
root_path = "C:\\Users\\Admin\\Desktop"
filepath = "other\\directories" # why not just rename it though
os.chdir(os.path.join(root_path, filepath))
Do these work for you?
I'm also curious why you have to chdir there; if it's possible, you should just run the python script from that directory.

Why is glob ignoring some directories?

I'm trying to find all *.txt files in a directory with glob(). In some cases, glob.glob('some\path\*.txt') gives an empty string, despite existing files in the given directories. This is especially true, if path is all lower-case or numeric.
As a minimal example I have two folders a and A on my C: drive both holding one Test.txt file.
import glob
files1 = glob.glob('C:\a\*.txt')
files2 = glob.glob('C:\A\*.txt')
yields
files1 = []
files2 = ['C:\\A\\Test.txt']
If this is by design, is there any other directory name, that leads to such unexpected behaviour?
(I'm working on win 7, with Python 2.7.10 (32bit))
EDIT: (2019) Added an answer for Python 3 using pathlib.

The problem is that \a has a special meaning in string literals (bell char).
Just double backslashes when inserting paths in string literals (i.e. use "C:\\a\\*.txt").
Python is different from C because when you use backslash with a character that doesn't have a special meaning (e.g. "\s") Python keeps both the backslash and the letter (in C instead you would get just the "s").
This sometimes hides the issue because things just work anyway even with a single backslash (depending on what is the first letter of the directory name) ...

I personally avoid using double-backslashes in Windows and just use Python's handy raw-string format. Just change your code to the following and you won't have to escape the backslashes:
import glob
files1 = glob.glob(r'C:\a\*.txt')
files2 = glob.glob(r'C:\A\*.txt')
Notice the r at the beginning of the string.
As already mentioned, the \a is a special character in Python. Here's a link to a list of Python's string literals:
https://docs.python.org/2/reference/lexical_analysis.html#string-literals

As my original answer attracted more views than expected and some time has passed. I wanted to add an answer that reliably solves this kind of problems and is also cross-plattform compatible. It's in python 3 on Windows 10, but should also work on *nix systems.
from pathlib import Path
filepath = Path(r'C:\a')
filelist = list(filepath.glob('*.txt'))
--> [WindowsPath('C:/a/Test.txt')]
I like this solution better, as I can copy and paste paths directly from windows explorer, without the need to add or double backslashes etc.

A python function with a complicated argument

I have a function in a python code whose argument is as follows:
save_geometry(r"""C:\Users\User0\Documents\test.txt """)
I want to modify the argument and be able to save to a different path with a different filename:
filename = "geometries.txt "
filepath = "D:/AllData/"
filefullpath = filepath + filename
Could someone help me how I should pass filefullpath to save_geometry? If there were no r in the argument of save_geometry, it would be easy. But I don't know how to deal with this r.

The r"" construct just tells Python that whatever's in the string should be interpreted as raw data.
"qw\n" == 'qw\n'
r"qw\n" == 'qw\\n'.
It's used because the "\" path separator is also used for newlines and such. You can skip it when putting in the argument; save_geometry(filefullpath) should do what you expect.

Note that the canonical way of putting together paths is os.path.join
path = os.path.join("D:\\", "AllData", "geometries.txt")
User3757614's answer addresses your concern of the raw string notation, but succinctly all the r"" notation does is tell Python that the following string should not treat \ as an escape character, but as a literal backslash. This is important since "C:\new folder" is actually
C:
ew folder
Since \n is a newline.

You cans use the os module to split your string into a folder path and file name.
e.g.
import os
pathname = os.path.dirname('C:\Users\User0\Documents\test.txt') #C:\Users\User0\Documents
filename = os.path.basename('C:\Users\User0\Documents\test.txt') #test.txt
Though you'll need to modify your path string because your \s will be interpreted and newline bytes