【Python之正则表达式与JSON】

a = ‘C|C++|C#|Python|Javascript’
print(a.index('Python')> -1)
print('Pythin' in a)

import re
a = ‘C|C++|C#|Python|Javascript’
r = re.findall('Python', a)     #返回一个列表
if len(r) > 0:
	print("字符串中包含Pyython")

import re
a = ‘C0C++4C#6Python1Javascript’
r = re.findall('\d',a)    #正则表达式中用“\d”统配数字
print(a)

import re
a = ‘C0C++4C#6Python1Javascript’
r = re.findall('\D',a)    #正则表达式中用“\D”匹配所有的非数字
print(a)

import re
a = 'abc,acc,adc,aec,afc,ahc'
r = re.findall('a[cf]c',s)    #匹配出acf或afc
print(r)

import re
a = 'abc,acc,adc,aec,afc,ahc'
r = re.findall('a[^cf]c',s)    #匹配出非acf和非afc
print(r)

import re
a = 'abc,acc,adc,aec,afc,ahc'
r = re.findall('a[c-f]c',s)    #匹配出a[c,d,e,f]c
print(r)

import re
a = ‘C0C++4C#6Python1Javascript’
r = re.findall('\d',a)    #正则表达式中用“\d”统配数字
print(a)

import re
a = ‘C0C++4C#6Python1Javascript’
r = re.findall('[0-9]',a)    #正则表达式中用“\d”统配数字等价于[0-9]
print(a)



```python
import re
a = ‘C0C++4C#6Python1Javascript’
r = re.findall('\w',a)    #正则表达式中用“\w”匹配所有的数字字母
print(a)

"\w" 单词字符集，可以匹配大小写字母，数字和_     等价于[A-Za-z0-9_]
“\W” 非单词字符集 &
“\s” 空白字符 包括空格，\t,\n,\r
“\S”  匹配非空白字符
. 匹配除\n以外的所有字符

import re
a ='python 1111java678php'
r = re.findall('[a-z]{3}',a)    #匹配连续的a-z的三个字符
print(r)


import re
a ='python 1111java678php'
r = re.findall('[a-z]{3，6}',a)    #匹配连续的a-z的3到6个字符
print(r)

import re
a ='python 1111java678php'
r = re.findall('[a-z]{3}',a)    #匹配连续的a-z的三个字符
print(r)

结果：
['python','java','php']     由于贪婪

import re
a ='python 1111java678php'
r = re.findall('[a-z]{3,6}?',a)    #非贪婪模式匹配
print(r)

结果：
['pyt’，hon','jav','php']     #由于非贪婪只匹配3个字符

*  匹配*前面的字符0次或无数次
+  匹配*前面的字符1次或无数次
？ 匹配*前面的字符0次或1次

import re 
a = '100001'
r = re.findall('\d{4,8}',qq)   #匹配4到8位数字
print(r)

import re 
a = '100001'
r = re.findall(^'\d{4,8}$',qq)   #边界匹配
print(r)

import re 
a = '10000000001'
r = re.findall(^'000$',qq)   #边界匹配
print(r)

import re
a = 'PythonPythonPythonPythonPythonPython'
r = re.findall('(Python){3}',a)
print(r)

import re
lanuage = 'PythonC#JavaPHP'
r = re.findall(‘c#.{1}’,lanuage,re.I |re.S)   
print(r)

re.I 忽略大小写   re.S 改变.的功能

import re 
lanuage = 'PythonC#JavaPHP'
r = re.sub(‘C#’,'GO',lanuage,1)
print(r)
# r = re.sub(‘需要被替换的字符’,‘替换后的字符',lanuage,被替换的次数（1表示1次，0表示无数次）)

import re 
lanuage = 'PythonC#JavaPHP'
r = lanuage.replace(‘C#’,'GO')
print(r)

import re 
lanuage = 'PythonC#JavaPHP'
def convert(value):
	pass
# 先匹配C#,将c#作为参数传给convert()函数，再将返回值用于替换C#
r = re.sub(‘C#’,convert,lanuage)
print(r)

import re
s = 'ABC3721D86'
r = re.match('\d',s)    
#从字符串首字母开始匹配，第一个字符不符合，则返回空
print(r)
r1 = re.search('\d',s)
# 搜索整个字符串，首字母对匹配不影响
print(r1)
# 他们都只匹配一次

# 获取life和python中间的内容
import re
s = 'life is short,i use python'
r = re.search('life.*python',s)
print(r.gruop())
group(0)默认返回完整匹配结果，要通过组号访问，需要从group(1)开始

import re
s = 'life is short,i use python, i love python'
r = re.search('life(.*)python(.*)python',s)
print(r.gruop(0))
print(r.gruop(1))
print(r.gruop(2))
# print(r.group(0,1,2))
print(r.groups())    #只会返回之间的字符串

import json
# json_str = "{'name':'qiyue','age':18}"    #错误，json字符串规定用“”
 json_str = '{"name":"qiyue","age":18}'    #json object
student = json.loads(json_str)
print(type(student))
print(student)
print(student['name'])
print(student['age'])

import json

json_str = '{"name":"qiyue","age":18,"flag":false},{"name":"qiyue","age":18}'
student = json.loads(json_str)
print(type(student))
print(student)
从字符串到语言的数据类型的转换，反序列化



序列化
import json
studeht = [		{"name":"qiyue","age":18,"flag":false},		{"name":"qiyue","age":18}]
json_str = json.dumps(student)
print(json_str)

json        python
object      dict
array 		list
string 		str 

json对象 json   json字符串
javascript    ECMSCRIPT规范和标准的实现

import re
api_response = "{'name': 'John', 'age': 30, 'city': 'New York'}"
pattern = r"'name':\s*'(\w+)'"
match = re.search(pattern, api_response)
if match:
    extracted_name = match.group(1)

import json
json_data = json.loads(extracted_json_string)
user_name = json_data['name']