正则表达式
1-1 [bh][aiu]t;
1-2 \w+ \w+;
1-3 \w+,\s\w+;
1-4 [A-Za-z_]+[\w_]+
python有效标识符的定义：
1.python中的标识符是区分大小写的。
2.标示符以字母或下划线开头，可包括字母，下划线和数字。
3.以下划线开头的标识符是有特殊意义的。
1-5 \d+(\s\w+)+
1-6 (1)^w{3}://.+com/?$ (2)^\w+://.+?\.\w{3}/?$
1-7 [\+-]?\d+
1-8 [\+-]?\d+[lL](注：python3已经把int和长整数合并了，没有123L这种表示法了)
1-9 [\+-]?\d*\.\d* (注: 此处用*是因为 .1 表示 0.1，1. 表示 1.0)
1-10 ([\+-]?\d*(\.\d*)?){2}i?
1-11 \w+[\w_-\.]*\w+@\w+\.\w{2,3}
电子邮件表示：用户名+@ +邮箱域名.com/org/cn...
有效电子邮件地址：用户名，可以自己选择。由字母、数字、点、减号或下划线组成。只能以数字或字母开头和结尾。
1-12 https?://[\w_\.-]*\w+/? (并不知道所谓的有效URL是什么规则，这答案也不知道是否能全匹配成功）
1-13 \s'(.+)'
1-14 1[0-2]
1-15
(1)\d{4}-(\d+)-(\d+)(?:-(\d{4}))?
(2)
[python] view plain copy
def check(card):
contexts = re.search(r'\d{4}-(\d+)-(\d+)(?:-(\d{4}))?', card).groups()
if not contexts[2] and len(contexts[0]) == 6 and len(contexts[1]) == 5:
return True
elif contexts[2] and len(contexts[0]) == 4 and len(contexts[1]) == 4 and len(contexts[2]) == 4:
return True
else:
return False
使用gendata.py
1-16
[python] view plain copy
from random import *
from string import ascii_lowercase as lc
from sys import *
from time import *
tlds = ('com', 'edu', 'net', 'org', 'gov')
with open('reddata.txt', 'w') as f:
for i in range(randrange(5, 11)):
dtint = randrange(maxsize)
dtstr = ctime(dtint)
llen = randrange(4, 8)
login =''.join(choice(lc) for j in range(llen))
dlen = randrange(llen,13)
dom =''.join(choice(lc) for j in range(dlen))
f.write('%s::%s@%s.%s::%d-%d-%d\n' % (dtstr, login, dom, choice(tlds), dtint, llen, dlen))
1-17
[python] view plain copy
import re
def Count(filename):
weeks = {}
with open(filename) as f:
contexts = f.read()
result = re.findall(r'(\w{3})\s\w{3}', contexts)
for i in result:
weeks[i] = weeks.get(i,0) + 1
return weeks
weeks = Count('reddata.txt')
print(weeks)
1-18 看了很多遍，还是无法理解这道题的意思
1-19 \w{3}\s.*?\s\d{4}
1-20 \w+@\w+\.\w{3}
1-21 \s(\w{3})\s
1-22 \s(\d{4})
1-23 \d{2}:\d{2}:\d{2}
1-24 (\w+)@(\w+\.\w{3})
1-25 (\w+)@(\w+)\.(\w{3})
1-26
[python] view plain copy
import re
def Replace(filename, mail):
with open(filename) as f:
contexts = f.read()
replace = re.sub(r'\w*@\w*\.\w{3}', mail, contexts)
print(replace)
Replace('reddata.txt', '[email protected]')
1-27
[python] view plain copy
import re
def print_time(filename):
with open(filename) as f:
contexts = f.read()
time = re.findall(r'\s(\w{3})\s(\d{2}).*?(\d{4})', contexts)
for t in time:
print(', '.join(t))
print_time('reddata.txt')
处理电话号码
1-28 (\d{3}-)?\d{3}-\d{3}
1-29 (\()?(\d{3})?(?(1)\) |-?)\d{3}-\d{3} 简单化：((\d{3}-)|(\d3\d3 ))?\d{3}-\d{3}
正则表达式应用程序
1-30、1-31、1-32 高深的题目，知识有限，暂时无法解决这些题。