python 2.10 json + 正则表达式
目录
1. 内置模块
1.1 json
json模块，是python内部的一个模块，可以将python的数据格式 转换为json格式的数据，也可以将json格式的数据转换为python的数据格式。
json格式，是一个数据格式（本质上就是个字符串，常用语网络数据传输）
# Python中的数据类型的格式
data = [
{"id": 1, "name": "武沛齐", "age": 18},
{"id": 2, "name": "alex", "age": 18},
('wupeiqi',123),
]
# JSON格式
value = '[{"id": 1, "name": "武沛齐", "age": 18}, {"id": 2, "name": "alex", "age": 18},["wupeiqi",123]]'
1.1.1 核心功能
json格式的作用？
跨语言数据传输，例如：
A系统用Python开发，有列表类型和字典类型等。
B系统用Java开发，有数组、map等的类型。
语言不同，基础数据类型格式都不同。
为了方便数据传输，大家约定一个格式：json格式，每种语言都是将自己数据类型转换为json格式，也可以将json格式的数据转换为自己的数据类型。
Python数据类型与json格式的相互转换：
-
数据类型 -> json ，一般称为：序列化
import json data = [ {"id": 1, "name": "武沛齐", "age": 18}, {"id": 2, "name": "alex", "age": 18}, ] res = json.dumps(data) print(res) # '[{"id": 1, "name": "\u6b66\u6c9b\u9f50", "age": 18}, {"id": 2, "name": "alex", "age": 18}]' res = json.dumps(data, ensure_ascii=False) print(res) # '[{"id": 1, "name": "武沛齐", "age": 18}, {"id": 2, "name": "alex", "age": 18}]' -
json格式 -> 数据类型，一般称为：反序列化
import json data_string = '[{"id": 1, "name": "武沛齐", "age": 18}, {"id": 2, "name": "alex", "age": 18}]' data_list = json.loads(data_string) print(data_list)
练习题
-
写网站，给用户返回json格式数据
-
安装flask模块，协助我们快速写网站（之前已安装过）
pip3 install flask -
使用flask写网站
import json from flask import Flask app = Flask(__name__) def index(): return "首页" def users(): data = [ {"id": 1, "name": "武沛齐", "age": 18}, {"id": 2, "name": "alex", "age": 18}, ] return json.dumps(data) app.add_url_rule('/index/', view_func=index, endpoint='index') app.add_url_rule('/users/', view_func=users, endpoint='users') if __name__ == '__main__': app.run()
-
-
发送网络请求，获取json格式数据并处理。
import json import requests url = "https://movie.douban.com/j/search_subjects?type=movie&tag=%E7%83%AD%E9%97%A8&sort=recommend&page_limit=5&page_start=20" res = requests.get( url=url, headers={ "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36" } ) # json格式 print(res.text) # json格式转换为python数据类型 data_dict = json.loads(res.text) print(data_dict)
1.1.2 类型要求
python的数据类型转换为 json 格式，对数据类型是有要求的，默认只支持：
+-------------------+---------------+
| Python | JSON |
+===================+===============+
| dict | object |
+-------------------+---------------+
| list, tuple | array |
+-------------------+---------------+
| str | string |
+-------------------+---------------+
| int, float | number |
+-------------------+---------------+
| True | true |
+-------------------+---------------+
| False | false |
+-------------------+---------------+
| None | null |
+-------------------+---------------+
data = [
{"id": 1, "name": "武沛齐", "age": 18},
{"id": 2, "name": "alex", "age": 18},
]
其他类型如果想要支持，需要自定义JSONEncoder 才能实现【目前只需要了解大概意思即可，以后项目开发中用到了还会讲解。】，例如：
import json
from decimal import Decimal
from datetime import datetime
data = [
{"id": 1, "name": "武沛齐", "age": 18, 'size': Decimal("18.99"), 'ctime': datetime.now()},
{"id": 2, "name": "alex", "age": 18, 'size': Decimal("9.99"), 'ctime': datetime.now()},
]
class MyJSONEncoder(json.JSONEncoder):
def default(self, o):
if type(o) == Decimal:
return str(o)
elif type(o) == datetime:
return o.strftime("%Y-%M-%d")
return super().default(o)
res = json.dumps(data, cls=MyJSONEncoder)
print(res)
1.1.3 其他功能
json模块中常用的是：
-
json.dumps，序列化生成一个字符串。 -
json.loads，发序列化生成python数据类型。 -
json.dump，将数据序列化并写入文件（不常用）import json data = [ {"id": 1, "name": "武沛齐", "age": 18}, {"id": 2, "name": "alex", "age": 18}, ] file_object = open('xxx.json', mode='w', encoding='utf-8') json.dump(data, file_object) file_object.close() -
json.load，读取文件中的数据并反序列化为python的数据类型（不常用）import json file_object = open('xxx.json', mode='r', encoding='utf-8') data = json.load(file_object) print(data) file_object.close()
1.3 正则表达式相关
当给你一大堆文本信息，让你提取其中的指定数据时，可以使用正则来实现。例如：提取文本中的邮箱和手机号
import re
text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀"
phone_list = re.findall("1[3|5|8|9]\d{9}", text)
print(phone_list)
1.3.1 正则表达式
1. 字符相关
-
wupeiqi匹配文本中的wupeiqiimport re text = "你好wupeiqi,阿斯顿发wupeiqasd 阿士大夫能接受的wupeiqiff" data_list = re.findall("wupeiqi", text) print(data_list) # ['wupeiqi', 'wupeiqi'] 可用于计算字符串中某个字符出现的次数 -
[abc]匹配a或b或c 字符。import re text = "你2b好wupeiqi,阿斯顿发awupeiqasd 阿士大夫a能接受的wffbbupqaceiqiff" data_list = re.findall("[abc]", text) print(data_list) # ['b', 'a', 'a', 'a', 'b', 'b', 'c']import re text = "你2b好wupeiqi,阿斯顿发awupeiqasd 阿士大夫a能接受的wffbbupqcceiqiff" data_list = re.findall("q[abc]", text) print(data_list) # ['qa', 'qc'] -
[^abc]匹配除了abc意外的其他字符。import re text = "你wffbbupceiqiff" data_list = re.findall("[^abc]", text) print(data_list) # ['你', 'w', 'f', 'f', 'u', 'p', 'e', 'i', 'q', 'i', 'f', 'f'] -
[a-z]匹配a~z的任意字符（ [0-9]也可以 ）。import re text = "alexrootrootadmin" data_list = re.findall("t[a-z]", text) print(data_list) # ['tr', 'ta'] -
.代指除换行符以外的任意字符。import re text = "alexraotrootadmin" data_list = re.findall("r.o", text) print(data_list) # ['rao', 'roo']import re text = "alexraotrootadmin" data_list = re.findall("r.+o", text) # 贪婪匹配 print(data_list) # ['raotroo']import re text = "alexraotrootadmin" data_list = re.findall("r.+?o", text) # 非贪婪匹配 print(data_list) # ['rao'] -
\w代指字母或数字或下划线（汉字）。import re text = "北京武沛alex齐北 京武沛alex齐" data_list = re.findall("武\w+x", text) print(data_list) # ['武沛alex', '武沛alex'] -
\d代指数字import re text = "root-ad32min-add3-admd1in" data_list = re.findall("d\d", text) print(data_list) # ['d3', 'd3', 'd1']import re text = "root-ad32min-add3-admd1in" data_list = re.findall("d\d+", text) print(data_list) # ['d32', 'd3', 'd1'] -
\s代指任意的空白符，包括空格、制表符等。import re text = "root admin add admin" data_list = re.findall("a\w+\s\w+", text) print(data_list) # ['admin add']
2. 数量相关
-
*重复0次或更多次import re text = "他是大B个，确实是个大2B。" data_list = re.findall("大2*B", text) print(data_list) # ['大B', '大2B'] -
+重复1次或更多次import re text = "他是大B个，确实是个大2B，大3B，大66666B。" data_list = re.findall("大\d+B", text) print(data_list) # ['大2B', '大3B', '大66666B'] -
?重复0次或1次import re text = "他是大B个，确实是个大2B，大3B，大66666B。" data_list = re.findall("大\d?B", text) print(data_list) # ['大B', '大2B', '大3B'] -
{n}重复n次import re text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" data_list = re.findall("151312\d{5}", text) print(data_list) # ['15131255789'] -
{n,}重复n次或更多次import re text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" data_list = re.findall("\d{9,}", text) print(data_list) # ['442662578', '15131255789'] -
{n,m}重复n到m次import re text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" data_list = re.findall("\d{10,15}", text) print(data_list) # ['15131255789']
3. 括号（分组）
-
提取数据区域
import re text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" data_list = re.findall("15131(2\d{5})", text) print(data_list) # ['255789']import re text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来15131266666呀" data_list = re.findall("15(13)1(2\d{5})", text) print(data_list) # [ ('13', '255789') ]import re text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" data_list = re.findall("(15131(2\d{5}))", text) print(data_list) # [('15131255789', '255789')] -
获取指定区域 + 或条件
import re text = "楼主15131root太牛15131alex逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" data_list = re.findall("15131(2\d{5}|r\w+太)", text) print(data_list) # ['root太', '255789']import re text = "楼主15131root太牛15131alex逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" data_list = re.findall("(15131(2\d{5}|r\w+太))", text) print(data_list) # [('15131root太', 'root太'), ('15131255789', '255789')]练习题
-
利用正则匹配QQ号码
[1-9]\d{4,} -
身份证号码
import re text = "dsf130429191912015219k13042919591219521Xkk" data_list = re.findall("\d{17}[\dX]", text) # [abc] print(data_list) # ['130429191912015219', '13042919591219521X']import re text = "dsf130429191912015219k13042919591219521Xkk" data_list = re.findall("\d{17}(\d|X)", text) print(data_list) # ['9', 'X']import re text = "dsf130429191912015219k13042919591219521Xkk" data_list = re.findall("(\d{17}(\d|X))", text) print(data_list) # [('130429191912015219', '9'), ('13042919591219521X', 'X')]import re text = "dsf130429191912015219k13042919591219521Xkk" data_list = re.findall("(\d{6})(\d{4})(\d{2})(\d{2})(\d{3})([0-9]|X)", text) print(data_list) # [('130429', '1919', '12', '01', '521', '9'), ('130429', '1959', '12', '19', '521', 'X')] -
手机号
import re text = "我的手机哈是15133377892，你的手机号是1171123啊？" data_list = re.findall("1[3-9]\d{9}", text) print(data_list) # ['15133377892'] -
邮箱地址
import re text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" email_list = re.findall("\w+@\w+\.\w+",text) print(email_list) # ['442662578@qq.com和xxxxx']import re text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" email_list = re.findall("[a-zA-Z0-9_-]+@[a-zA-Z0-9_-]+\.[a-zA-Z0-9_-]+", text, re.ASCII) print(email_list) # ['442662578@qq.com', 'xxxxx@live.com']import re text = "楼主太牛逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" email_list = re.findall("\w+@\w+\.\w+", text, re.ASCII) print(email_list) # ['442662578@qq.com', 'xxxxx@live.com']import re text = "楼主太牛44266-2578@qq.com逼了，在线想要 442662578@qq.com和xxxxx@live.com谢谢楼主，手机号也可15131255789，搞起来呀" email_list = re.findall("(\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*)", text, re.ASCII) print(email_list) # [('44266-2578@qq.com', '-2578', '', ''), ('xxxxx@live.com', '', '', '')] -
补充代码，实现获取页面上的所有评论（已实现），并提取里面的邮箱。
# 先安装两个模块 pip3 install requests pip3 install beautifulsoup4import re import requests from bs4 import BeautifulSoup res = requests.get( url="https://www.douban.com/group/topic/79870081/", headers={ 'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.163 Safari/537.36', } ) bs_object = BeautifulSoup(res.text, "html.parser") comment_object_list = bs_object.find_all("p", attrs={"class": "reply-content"}) for comment_object in comment_object_list: text = comment_object.text print(text) # 请继续补充代码，提取text中的邮箱地址
4. 起始和结束
上述示例中都是去一段文本中提取数据，只要文本中存在即可。
但，如果要求用户输入的内容必须是指定的内容开头和结尾，比就需要用到如下两个字符。
^开始$结束
import re
text = "啊442662578@qq.com我靠"
email_list = re.findall("^\w+@\w+.\w+$", text, re.ASCII)
print(email_list) # []
import re
text = "442662578@qq.com"
email_list = re.findall("^\w+@\w+.\w+$", text, re.ASCII)
print(email_list) # ['442662578@qq.com']
这种一般用于对用户输入数据格式的校验比较多，例如：
import re
text = input("请输入邮箱：")
email = re.findall("^\w+@\w+.\w+$", text, re.ASCII)
if not email:
print("邮箱格式错误")
else:
print(email)
5. 特殊字符
由于正则表达式中 * . \ { } ( ) 等都具有特殊的含义，所以如果想要在正则中匹配这种指定的字符，需要转义，例如：
import re
text = "我是你{5}爸爸"
data = re.findall("你{5}爸", text)
print(data) # []
import re
text = "我是你{5}爸爸"
data = re.findall("你\{5\}爸", text)
print(data)
1.3.2 re模块
python中提供了re模块，可以处理正则表达式并对文本进行处理。
-
findall，获取匹配到的所有数据
import re text = "dsf130429191912015219k13042919591219521Xkk" data_list = re.findall("(\d{6})(\d{4})(\d{2})(\d{2})(\d{3})([0-9]|X)", text) print(data_list) # [('130429', '1919', '12', '01', '521', '9'), ('130429', '1959', '12', '19', '521', 'X')] -
match，从起始位置开始匹配，匹配成功返回一个对象，未匹配成功返回None
import re text = "大小逗2B最逗3B欢乐" data = re.match("逗\dB", text) print(data) # Noneimport re text = "逗2B最逗3B欢乐" data = re.match("逗\dB", text) if data: content = data.group() # "逗2B" print(content) -
search，浏览整个字符串去匹配第一个，未匹配成功返回None
import re text = "大小逗2B最逗3B欢乐" data = re.search("逗\dB", text) if data: print(data.group()) # "逗2B" -
sub，替换匹配成功的位置
import re text = "逗2B最逗3B欢乐" data = re.sub("\dB", "沙雕", text) print(data) # 逗沙雕最逗沙雕欢乐import re text = "逗2B最逗3B欢乐" data = re.sub("\dB", "沙雕", text, 1) print(data) # 逗沙雕最逗3B欢乐 -
split，根据匹配成功的位置分割
import re text = "逗2B最逗3B欢乐" data = re.split("\dB", text) print(data) # ['逗', '最逗', '欢乐']import re text = "逗2B最逗3B欢乐" data = re.split("\dB", text, 1) print(data) # ['逗', '最逗3B欢乐'] -
finditer
import re text = "逗2B最逗3B欢乐" data = re.finditer("\dB", text) for item in data: print(item.group())import re text = "逗2B最逗3B欢乐" data = re.finditer("(?P<xx>\dB)", text) # 命名分组 for item in data: print(item.groupdict())text = "dsf130429191912015219k13042919591219521Xkk" data_list = re.finditer("\d{6}(?P<year>\d{4})(?P<month>\d{2})(?P<day>\d{2})\d{3}[\d|X]", text) for item in data_list: info_dict = item.groupdict() print(info_dict)
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