Python在文件开头添加Unicode字符

Question

I use a script to update the version of each AssemblyVersion.cs file of a .NET project. It always worked perfectly, but since a format my PC, it adds unicode character at the start of each .cs file edited. Like this:

using System.Reflection;
using System.Runtime.InteropServices;
using System.Security;

I use this code to open a file:

with open(fname,  "r") as f:
    out_fname = fname + ".tmp"
    out = codecs.open(out_fname, "w", encoding='utf-8')
    textInFile=""
    for line in f:
        textInFile += (re.sub(pat, s_after,line))
    out.write(u'\uFEFF')
    out.write(textInFile)
    out.close()
os.remove(fname)
os.rename(out_fname, fname)

I've also tried, as wrote here , to use io instead of codecs , but nothing is changed.

On other teammates' PCs it works with the same configuration (Win10 and IronPython 2.7).

What can I try to solve this issue? Where can I looking for the problem?

Thanks

Answer 1

It seems that the files at your file system are using ISO-8859-1 encoding, while you are adding the UT8 BOM marker at the beginning of each file.

After your code does it's job, you get a file with UTF-8 BOM + ISO-8859-1 meta at the beginning.

I would check the encoding of your input files before modification with Notepad++ (or any other editor) just to see if the scenario I described is valid. If it is, you will need to read your input files with a different encoding in order to avoid the metadata:

with open(fname,  "r",  "ISO-8859-1") as f:
    ...