python文件操作基本练习

python文件操作基本练习

1、批量修改文件名

import os
import sys

path = "E:\作业\python\homework"

pre = 0
s3 = ".txt"
for i in range(1, 5):
    pre = pre + 1
    oldname = str(pre) + s3
    print("name = " + str(pre) + s3)
    s2 = input("Enter your input: ")
    s1 = str(pre)
    newname = s2 + s1 + s3
    os.rename(path + "\\" + oldname, path + "\\" + newname)
    print("success: " + newname)
    print("----------------------------------------------------------")

2、读取一个文件，显示除了以#号开头的行以外的所有行

file = open("E:\作业\python\homework\shu5.txt",'r')
r = file.readlines()
for i in r:
    if i[0] == '#':
        continue
    else:
        print(i)
file.close()

3、已知文本文件中存放了若干个数字，请编写程序读取所有数字，排序以后进行输出

fl = open('E:\作业\python\homework\shu6.txt')
l = []
sort = []
for lines in fl.readlines():
   lines = lines.replace("\n", "")
   l.append(lines)
print('\n', 'the original file is:', l)
sort = sorted(l)
print('\n', 'the sorted file is:', sort)

4、打开一个英文的文本文件，将该文件中的每一个字母加密后写入到一个新文件，加密的方法是：将A变成B,B变成C,……，Y变成Z,Z变成A;a变成b,b变成c……,z变成a,其它字符不变化

file=open("E:\作业\python\homework\shu2.txt","r")
con=file.readline()
list=list(con)
file.close()
for i in range(0,len(list)):
    if list[i].islower():
        if list[i]=='z':
            list[i]=chr(97)
            continue
        num=ord(list[i])
        list[i]=chr(num+1)
    if list[i].isupper():
        if list[i]=='Z':
            list[i]=chr(65)
            continue
        num=ord(list[i])
        list[i]=chr(num+1)
new_Str=''.join(list)
print(new_Str)
file=open("3.txt","w+")
file.write(new_Str)
file.close()

5、打开一个英文文本文件，将其中大写字母变成小写，小写字母变为大写

txt = open(r"E:\作业\python\homework\shu7.txt")
r = txt.read()
print("修改前的字符：" + r)
txt1 = r.swapcase()
print("修改后的字符：" + txt1)