1、Python自有模块正则

import re

# re.match只匹配字符串的开始，如果字符串开始不符合正则表达式，则匹配失败，函数返回None
print(re.match("aaa","aaaabbb").group())   #在起始位置匹配
print(re.match("aaa","abbbaaa"))           #不在起始位置匹配，返回None

# re.search扫描整个字符串并返回第一个成功的匹配
print(re.search("haha","geinizhanggognzi").group())

# re.findall从左到右扫描字符串，按顺序返回匹配，如果无匹配结果则返回空列表
print(re.findall("\d","queshihenlihai"))
print(re.findall("\d","zhengchangfasheng"))

# sub用于替换字符串中的匹配项
print(re.sub("g..t","good","goot geet up"))
# split返回切割后的列表
print(re.split("\+","123+456*789+abcd"))

1 # ['AD123453', 'AC342123', 'AR343212']
2 # [A-Z]{2}\d{6}
3 
4 # ^(13|14|15|17|18)\d{9}
5 # ^1[34578]\d{9}

2、Python第三方模块操作MySQL

连接数据库：

import mysql.connector
config = {
    "host":"127.0.0.1",
    "user":"root",
    "passwd":"vertrigo",
    "port":3306,
    "db":"test",
    "charset":"utf8"
}

try:
    db = mysql.connector.connect(**config)
except mysql.connector.Error as e:
    print("连接数据库失败！",str(e))

插入数据：

2 cursor = db.cursor(buffered=True)   #buffered=True会把结果集保存到本地并一次性返回，这样可以提高性能
try:
    #第一种：直接字符串插入方式
    # sql_insert1="insert into student (name, age) values ('xiao', 27)"
    # cursor.execute(sql_insert1)

    #第二种：元组连接插入方式
    sql_insert2="insert into student (name, age) values (%s, %s)"
    #此处的%s为占位符，而不是格式化字符串，所以age用%s
    # data=('xiaoqiang',18)
    # cursor.execute(sql_insert2,data)
    data = [("xiao",20),
            ("xian",25),
            ("rourou",27),
            ("juju",28)]
    cursor.executemany(sql_insert2,data)

    #如果表引擎为Innodb，执行完成后需执行commit进行事务提交
    db.commit()
    #cursor.execute('commit')
except mysql.connector.Error as e:
    print('插入失败！', str(e))
finally:
    cursor.close()
    db.close()

删除数据：

cursor = db.cursor(buffered=True)
try:
    sql_del = "delete from student where name=%s and age=%s"
    data_del = [
        ("jin",28),
        ("songhao",27)]
    cursor.executemany(sql_del,data_del)
    db.commit()
except mysql.connector.Error as e:
    print("删除数据失败！",str(e))
finally:
    cursor.close()
    db.close()

修改数据：

cursor = db.cursor(buffered=True)
try:
    sql_update = "update student set age = 28 where name='nan'"
    cursor.execute(sql_update)
    db.commit()
except mysql.connector.Error as e:
    print('修改数据失败',str(e))
finally:
    cursor.close()
    db.close()

查询数据：

cursor = db.cursor(buffered=True)
try:
    # sql_select1 = "select * from student where age>%s"
    # cursor.execute(sql_select1,(1,))

    sql_select2 = "select * from student where age>%s"
    cursor.execute(sql_select2,(26,))
    datas1 = cursor.fetchall()         #如果在后加上[1]代表是取第一条数据

    cursor.execute(sql_select2,(20,))
    datas2 = cursor.fetchone()[1]      #如果在后加上[1]代表是取第一个字段
    datas3 = cursor.fetchmany(5)

    print(datas1)
    print(datas2)
    print(datas3)
except mysql.connector.Error as e:
    print("查询数据失败！",str(e))
finally:
    cursor.c