File names have a `hidden' m character prepended

Question

I have a simple python script which produces some data in a Neutron star mode. I use it to automate file names so I don't later forget the inputs. The script succesfully saves the file as

some_parameters.txt

but when I then list the files in terminal I see

msome_parameters.txt

The file name without the "m" is still valid and trying to call the file with the m returns

$ ls m*
No such file or directory

So I think the "m" has some special meaning of which numerous google searches do not yields answers. While I can carry on without worrying, I would like to know the cause. Here is how I create the file in python

# chi,epsI etc are all floats. Make a string for the file name
file_name = "chi_%s_epsI_%s_epsA_%s_omega0_%s_eta_%s.txt" % (chi,epsI,epsA,omega0,eta) 

# a.out is the compiled c file which outputs data
os.system("./a.out >  %s" % (file_name) )

Any advise would be much appreciated, usually I can find the answer already posted in the stackoverflow but this time I'm really confused.

Answer 1

You have a file with some special characters in the name which is confusing the terminal output. What happens if you do ls -l or (if possible) use a graphical file manager - basically, find a different way of listing the files so you can see what's going on. Another possibility would be to do ls > some_other_filename and then look at the file with a hex editor.