Converting a list to string with prefix and suffix

Question

I have this list:

myist = ['0', '1', '2', '3']

and I want to execute something via os.system() where multiple files are used in one line:

cat file0.txt file1.txt file2.txt file3.txt > result.txt

but I'm not sure how to add a suffix when joining the list. This:

os.system("cat file" + ' file'.join(mylist) +".txt > result.txt" )

will give me:

cat file0 file1 file2 file3.txt > result.txt

but what I want is this:

cat file0.txt file1.txt file2.txt file3.txt > result.txt

So what I'm searching for is something like 'prefix'.join(mylist).'suffix'. How can I do this without using for loops?

Answer 1

You could just add the suffix to the start of the string:

os.system("cat file" + '.txt file'.join(mylist) +".txt > result.txt")

Or you could use string formatting with the map function:

os.system("cat " + ' '.join(map('file{0}.txt'.format, mylist)) + " > result.txt")

Answer 2

Using a generator expression:

print  "cat " + " ".join("file%d.txt" % int(d) for d in mylist) + " > result.txt"