使用Python寻找构建简单的文件路径查找和替换程序

Question

I think I should start this off by saying that I'm very new to Python. I've gone through some lessons and picked up a fairly solid understanding of the fundamentals, but my skill set is still very limited and the results I achieve on my own will probably be very crude. I'm currently trying to put together a find and replace program that can output edited paths. See below:

filepaths = [
"\wwwtest\test\site\services\cogs\index.html",
"\wwwtest\test\site\dba\index.html"
]

find = "\wwwtest\test\site"

replace_one = "http:\\www.test.com"

replace_two = "https:\\www.test.com"

for paths in filepaths:
    print(paths.replace(find, replace_one))
    print(paths.replace(find, replace_two))

So in essence, what I'm trying to do is input file paths and output URLs. Running the above code in a shell yields the following results:

http:\www.test.com\services\cogs\index.html
https:\www.test.com\services\cogs\index.html
http:\www.test.com\dba\index.html
https:\www.test.com\dba\index.html

I think I'm more or less on the right track, but obviously there are some issues with the output, namely the removal of the second \\ preceding the www of each URL. I imagine that this is the result of Python interpreting the double \\ as some kind of special character, but I've been unable to determine how best to resolve this issue.

Following the successful replacement of the first block of the path/URL, I'll also need to replace each \\ with / (or maybe this should come first?) which is creating its own set of issues. The following code is what I've tried so far:

urls = [
    "http:\www.test.com\services\cogs\index.html",
    "https:\www.test.com\services\cogs\index.html"
    ]

find = '\'

replace = '/'

for paths in urls:
    print(paths.replace(find, replace))

This code yields the following:

SyntaxError: EOL while scanning string literal

I believe I'm missing some information regarding the use of slashes in Python. Any advice on how best to develop such a program, and also how to make the code efficient would be very much appreciated. I also realize that hard coding the paths I want to manipulate into the program probably isn't the most effective way of doing this, but I may leave that for a separate question to keep this post from getting longer than it already is (although any advice on how to properly read from and write to text files for this example would also be appreciated).

Thank you, D

Answer 1

In python, \\ is the escape character, so if you want to literally represent \\ you have to repeat it twice, ie "C:\\\\Windows\\\\path" or define it as a string literal in place by putting an r before the string, r"C:\\Windows\\path"

Here are some good examples to show you how it operates.

Answer 2

The \\ is the beginning of an escape sequence .

In the first part if you wish to output two "\\\\" you will need to write it like this:

replace_one = "http:\\\\www.test.com"

replace_two = "https:\\\\www.test.com"

if you wish to find a \\ you will need to do it like this to escape the escape sequence:

find = '\\'

Answer 3

Every time you want to use \\ , use instead \\\\ . Consequently, if you want \\\\ , use \\\\\\\\ :

filepaths = [
"\\wwwtest\\test\\site\\services\\cogs\\index.html",
"\\wwwtest\\test\\site\\dba\\index.html"
]

find = "\\wwwtest\\test\\site"

replace_one = "http:\\\\www.test.com"

replace_two = "https:\\\\www.test.com"

for paths in filepaths:
    print(paths.replace(find, replace_one))
    print(paths.replace(find, replace_two))

and

urls = [
    "http:\\\\www.test.com\\services\\cogs\\index.html",
    "https:\\\\www.test.com\\services\\cogs\\index.html"
    ]

find = '\\'

replace = '/'

for paths in urls:
    print(paths.replace(find, replace))

should fix your problem.