Python file read-write-reads all lines of a file, writes another file after processing

1 #Filename:file_read_and_write.py2 #Open the file, cnames read all the rows, store them in the list, and loop each line at the beginning with the ordinal number 1,2,3,43With open (r'File/companies.txt') as F1:4CNAMEs =F1.readlines ()5      forIinchRange (0,len (cnames)):6Cnames[i] = str (i+1) +'.'+"'+Cnames[i]7 8 #writes the processed cnames to a new file9With open (r'File/scompanies.txt','W') as F2:TenF2.writelines (cnames)

Input: Companies.txt

Googletencentalibababaidu

Output: Scompanies.txt

1.google2. Tencent3. Alibaba4.baidu  

Python file read-write-reads all lines of a file, writes another file after processing