字符串操作，英文词频统计预处理

作业要求来源于：https://edu.cnblogs.com/campus/gzcc/GZCC-16SE2/homework/2646
解析身份证号：生日、性别、出生地等。

#! /use/bin/python
# -*- coding: UTF-8 -*-
def check_idcard(id_card):
    if id_card is None or id_card.strip() =='':
        print('请输入身份证信息')
        exit(-1)

        if len(id_card) !=18:
            print('身份证只有18位')

            print('地址信息：%s'% id_card[0:6])
            print('生日信息：%s' % id_card[0:14])
            print('后4位校验码：%s' % id_card[14:18])

            if __name__=='__mian__':
            check_idcard('450403197503271234')

凯撒密码编码与解码:

#-*-coding:utf-8-*-
__author__ = 007
__date__ = 2019 / 03/ 04
def encryption():
    str_raw = raw_input("请输入明文：")
    k = input("请输入位移值：")
    str_change = str_raw.lower()
    str_list = list(str_change)
    str_list_encry = str_list
    i = 0
    while i < len(str_list):
        if ord(str_list[i]) < 123-k:
            str_list_encry[i] = chr(ord(str_list[i]) + k)
        else:
            str_list_encry[i] = chr(ord(str_list[i]) + k - 26)
        i = i+1
    print "加密结果为："+"".join(str_list_encry)

def decryption():
    str_raw = raw_input("请输入密文：")
    k = input("请输入位移值：")
    str_change = str_raw.lower()
    str_list = list(str_change)
    str_list_decry = str_list
    i = 0
    while i < len(str_list):
        if ord(str_list[i]) >= 97+k:
            str_list_decry[i] = chr(ord(str_list[i]) - k)
        else:
            str_list_decry[i] = chr(ord(str_list[i]) + 26 - k)
        i = i+1
    print "解密结果为："+"".join(str_list_decry)

while True:
    print u"1. 加密"
    print u"2. 解密"
    choice = raw_input("请选择：")
    if choice == "1":
        encryption()
    elif choice == "2":
        decryption()
    else:
        print u"您的输入有误！"

#if __name__ == "__main__":
#    main

网址观察与批量生成:

for i in range(6, 254):
    url = 'http://news.gzcc.cn/html/xiaoyuanxinwen/{}.html'.format(i)
print(url)

2.英文词频统计预处理

• 下载一首英文的歌词或文章或小说，保存为utf8文件。
• 从文件读出字符串。
• 将所有大写转换为小写
• 将所有其他做分隔符（,.？！）替换为空格
• 分隔出一个一个的单词
• 并统计单词出现的次数。

• text="Mr. Johnson had never been up in an aerophane before and he had read a lot about air accidents," \
       " so one day when a friend offered to take him for a ride in his own small phane, " \
       "Mr. Johnson was very worried about accepting." \
       " Finally, however, his friend persuaded him that it was very safe, and Mr. Johnson boarded the plane."
  print(text.lower())
  str=", . ! ? - ' :"
  for s in  str:
      text=text.replace(s,'')
      print(text.split())
      print(text.count('you'),text.count('her'))