Python文件讀寫 - 讀一個文件所有行，加工后寫另一個文件

 

#Filename: file_read_and_write.py
#打開文件，cNames讀取所有行，儲存在列表中，循環對每一行在起始處加上序號1，2，3，4
with open(r'file/companies.txt') as f1:
    cNames = f1.readlines()
    for i in range(0,len(cNames)):
        cNames[i] = str(i+1) + '.' + '' + cNames[i]

#將處理過的cNames寫入新的文件中
with open(r'file/scompanies.txt','w') as f2:
    f2.writelines(cNames)

 

輸入: companies.txt

google
tencent
alibaba
baidu

 

輸出：scompanies.txt

1.google
2.tencent 3.alibaba 4.baidu