python面试专题 - 高级用法

Author: zonezoen

python/interview/__init__.py

@@ -0,0 +1,7 @@
+# -*- coding: utf-8 -*-
+__auth__ = 'zone'
+__date__ = '2019/8/4 下午3:32'
+'''
+公众号：zone7
+小程序：编程面试题库
+'''

python/interview/with_keyword.py

@@ -0,0 +1,60 @@
+# -*- coding: utf-8 -*-
+__auth__ = 'zone'
+__date__ = '2019/8/4 下午3:33'
+'''
+公众号：zone7
+小程序：编程面试题库
+'''
+
+import contextlib
+import pymysql
+
+# 原始用法
+conn = pymysql.connect()
+cur = conn.cursor()
+sql = "select * from users"
+cur.execute(sql)
+print(cur.fetchone())
+conn.commit()
+cur.close()
+conn.close()
+
+
+class MysqlDb():
+    def __init__(self, database, host="localhost", user="root", prot=3306, password="root", charset="utf8mb4"):
+        self.conn = pymysql.connect(host=host, user=user, password=password, port=prot, database=database,
+                                    cursorclass=pymysql.cursors.DictCursor, charset=charset)
+        self.cur = self.conn.cursor()
+
+    def __enter__(self):
+        return self.cur
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.conn.commit()
+        self.cur.close()
+        self.conn.close()
+
+
+with MysqlDb(database="test", ) as db:
+    sql = "select * from users"
+    db.execute(sql)
+    print(db.fetchone())
+    intert_sql = "INSERT INTO `users` (`name`, `password`, `age`, `sex`) VALUES (%s, %s, %s, %s)"
+    db.execute(intert_sql, ('zone7', 'pwd', "18", "man"))
+
+
+@contextlib.contextmanager
+def get_mysql_cur(database, host="localhost", user="root", prot=3306, password="root", charset="utf8mb4"):
+    conn = pymysql.connect(host=host, user=user, password=password, port=prot, database=database,
+                           cursorclass=pymysql.cursors.DictCursor, charset=charset)
+    cur = conn.cursor()
+    yield cur
+    conn.commit()
+    cur.close()
+    conn.close()
+
+
+with get_mysql_cur(database="test", ) as db:
+    sql = "select * from users"
+    db.execute(sql)
+    print(db.fetchone())