Edit text file to add row numbers (begins in 1 ) - Python

[mcff]

If this is the input:
a
b
c

I want to have this:
1 a
2 b
3 c

I have this code:

infile=open('resultado.txt','r')
lines=infile.readlines()
infile.close()
outtext=['%d %s' % (i,line) for i, line in enumerate(lines)]
outfile = open ('res.txt','w')
outfile.write(str(''.join(outtext)))
outfile.close()

but my row number begins in 0

[mcff]

Sorry it was easy, I just added i+1:

infile=open('resultado.txt','r')
lines=infile.readlines()
infile.close()
outtext=['%d %s' % (i+1,line) for i, line in enumerate(lines)]
outfile = open ('res.txt','w')
outfile.write(str(''.join(outtext)))
outfile.close()

[bvdet]

Instead of (i,line), use (i+1,line).