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replacing string from '\' into '/' Python

I've been strugling with some code where i need to change simple \ into / in Python. Its a path of file- Python doesn't read path of file in Windows'es way, so i simply want to change Windows path for Python to read file correctly.
I want to parse some text from game to count statistics. Im Doing it this way:
import re
pathNumbers = "D:\Gry\Tibia\packages\TibiaExternal\log\test server.txt"
pathNumbers = re.sub(r"\\", r"/",pathNumbers)
fileNumbers = open (pathNumbers, "r")
print(fileNumbers.readline())
fileNumbers.close()
But the Error i get back is
----> 6 fileNumbers = open (pathNumbers, "r") OSError: [Errno 22] Invalid argument: 'D:/Gry/Tibia/packages/TibiaExternal\test server.txt'
And the problem is, that function re.sub() and .replace(), give the same result- almost full path is replaced, but last char to change always stays untouched.
Do you have any solution for this, because it seems like changing those chars are for python a sensitive point.

Simple answer:
If you want to use paths on different plattforms join them with
os.path.join(path,*paths)
This way you don't have to work with the different separators at all.
Answer to what you intended to do:
The actual problem is, that your pathNumbers variable is not raw (leading r in definition), meaning that the backslashes are used as escape characters. In most cases this does not change anything, because the combinations with the following characters don't have a meaning. \t is the tab character, \n would be the newline character, so these are not simple backslash characters any more.
So simply write
pathNumbers = r"D:\Gry\Tibia\packages\TibiaExternal\log\test server.txt"

silly file reading question for new python user

I am simply trying to define a path and file name then use pandas.read_csv()
in the variable display of spyder, the path and file name appear correct, but in reality they have double \\. I know this has got to be something really stupid...
siteinfopath=r'C:\Users\cpsei\Documents'
siteinfofile=siteinfopath+'\grav_stats.csv'
grav_stats=pd.read_csv(siteinfofile)
When i run the script I get the following error message:
FileNotFoundError: [Errno 2] File
b'C:\Users\cpsei\Documents\grav_stats.csv' does not exist:
b'C:\Users\cpsei\Documents\grav_stats.csv'
and when I type
siteinfofile
Out[145]: 'C:\\Users\\cpsei\\Documents\\grav_stats.csv'
Why the double \. In the variable viewer the path is correct.

You see double \\ instead of one, because \ is used in python as escape character - it informs that this \ character and next character should be threated in special way. For example:
\t - means TAB
\r - is carriage return - cursor moves to the beginning of the line
\n - is new line - cursor moves to beginning of new line
If however you want just plain simple \, you have to use \\ - first one informs as usual that there is some special character, and next informs that this special character is actually \.
You can read more about it ie on https://docs.python.org/3/tutorial/introduction.html#strings - there is a lot of very good examples :)
So, everything is OK, your strings work as expected. If you want to see how this string looks like, and not how it is constructed, print it:
>>> print(siteinfofile)
C:\Users\cpsei\Documents\grav_stats.csv
Are you sure path is correct and you can read this file? That's the only advice I can think of here...

IO ERROR(ERRNO 20) while Accessing a file inside a folder in python

This is a code for accessing a file inside a folder using with open() as:{} option.
with open("DATABASE\password.txt") as _2_:
password=_2_.readlines()
with open("DATABASE/names.txt") as _3_:
names=_3_.readlines()
with open("DATABASE\email.txt") as _4_:
email=_4_.readlines()
In this code, if I put "DATABASE\names.txt", as I did for password and email; instead of "DATABASE/names.txt"; it does not work. Please Tell me the reason for the same.

You need to add another backslash. Example: open("path\\to\\file.txt")
Your errors are happening because you need to escape the backslash by adding another one. Such a thing won't happen with /.

You need to escape the \, use raw string r or forward slashes as you have already tried:
"DATABASE\\names.txt" # double \
r"DATABASE\names.txt" # raw string
"DATABASE/names.txt" # use forward slashes
\n is a newline character.
In [7]: print "DATABASE\names.txt" # interpreted as two lines
DATABASE
ames.txt
In [8]: print r"DATABASE\names.txt"
DATABASE\names.txt
A backslash has a special meaning in python, it is used to escape characters.

removing weird double quotes (from excel file) in python string

I'm loading in an excel file to python3 using xlrd. They are basically lines of text in a spreadsheet. On some of these lines are quotation marks. For example, one line can be:
She said, "My name is Jennifer."
When I'm reading them into python and making them into strings, the double quotes are read in as a weird double quote character that looks like a double quote in italics. I'm assuming that somewhere along the way, python read in the character as some foreign character rather than actual double quotes due to some encoding issue or something. So in the above example, if I assign that line as "text", then we'll have something like the following (although not exactly since I don't actually type out the line, so imagine "text" was already assigned beforehand):
text = 'She said, “My name is Jennifer.”'
text[10] == '"'
The second line will spit out a False because it doesn't seem to recognize it as a normal double quote character. I'm working within the Mac terminal if that makes a difference.
My questions are:
1. Is there a way to easily strip these weird double quotes?
2. Is there a way when I read in the file to get python to recognize them as double quotes properly?

I'm assuming that somewhere along the way, python read in the character as some foreign character
Yes; it read that in because that's what the file data actually represents.
rather than actual double quotes due to some encoding issue or something.
There's no issue with the encoding. The actual character is not an "actual double quote".
Is there a way to easily strip these weird double quotes?
You can use the .replace method of strings as you would normally, to either replace them with an "actual double quote" or with nothing.
Is there a way when I read in the file to get python to recognize them as double quotes properly?
If you're looking for them, you can compare them to the character they actually are.
As noted in the comment, they are most likely U+201C LEFT DOUBLE QUOTATION MARK and U+201D RIGHT DOUBLE QUOTATION MARK. They're used so that opening and closing quotes can look different (by curving in different directions), which pretty typography normally does (as opposed to using " which is simply more convenient for programmers). You represent them in Python with a Unicode escape, thus:
text[10] == '\u201c'
You could also have directly asked Python for this info, by asking for text[10] at the Python command line (which would evaluate that and show you the representation), or explicitly in a script with e.g. print(repr(text[10])).

How can I read blackslashes from a file correctly?

The following code:
key = open("C:\Scripts\private.ppk",'rb').read()
reads the file and assigns its data to the var key.
For a reason, backslashes are multiplied in the process. How can I make sure they don't get multiplied?

You ... don't. They are escaped when they are read in so that they will process properly when they are written out / used. If you're declaring strings and don't want to double up the back slashes you can use raw strings r'c:\myfile.txt', but that doesn't really apply to the contents of a file you're reading in.
>>> s = r'c:\boot.ini'
>>> s
'c:\\boot.ini'
>>> repr(s)
"'c:\\\\boot.ini'"
>>> print s
c:\boot.ini
>>>
As you can see, the extra slashes are stored internally, but when you use the value in a print statement (write a file, test for values, etc.) they're evaluated properly.

You should read this great blog post on python and the backslash escape character.
And under some circumstances, if
Python prints information to the
console, you will see the two
backslashes rather than one. For
example, this is part of the
difference between the repr() function
and the str() function.
myFilename =
"c:\newproject\typenames.txt" print
repr(myFilename), str(myFilename)
produces
'c:\newproject\typenames.txt'
c:\newproject\typenames.txt

Backslashes are represented as escaped. You'll see two backslashes for each real one existing on the file, but that is normal behaviour.
The reason is that the backslash is used in order to create codes that represent characters that cannot be easily represented, such as new line '\n' or tab '\t'.

Are you trying to put single backslashes in a string? Strings with backslashes require and escape character, in this case "\". It will print to the screen with a single slash

In fact there is a solution - using eval, as long as the file content can be wrapped into quotes of some kind. Following worked for me (PATH contains some script that executes Matlab):
MATLAB_EXE = "C:\Program Files (x86)\MATLAB\R2012b\bin\matlab.exe"
content = open(PATH).read()
MATLAB_EXE in content # False
content = eval(f'r"""{content}"""')
MATLAB_EXE in content # True
This works by evaluating the content as python string literal, making double escapes transform into single ones. Raw string is used to prevent escapes forming special characters.