class Student:
 pass
# 或者
class Developer(object):
 pass

class Developer(object):
 # 定义类属性
 name = 'WuXiaolong'
 site = 'http://wuxiaolong.me/'
 # 变量名两个下划线开头，定义私有属性, 这样在类外部无法直接进行访问，类的私有方法也是如此
 __sex = 0
 # 定义构造方法
 def __init__(self, name, site, sex):
 self.name = name
 self.site = site
 self.__sex = sex
 # 类方法
 def get_sex(self):
 return self.__sex
 def set_sex(self, sex):
 self.__sex = sex
# 调用：
if __name__ == '__main__':
 # 实例化类
 developer = Developer('wxl', 'http://wuxiaolong.me/', 1) # 实例化成变量
 print(developer.site, developer.get_sex()) # 访问类的属性和方法

class Developer(object):
 # 定义类属性
 name = 'WuXiaolong'
 site = 'http://wuxiaolong.me/'
 # 变量名两个下划线开头，定义私有属性, 这样在类外部无法直接进行访问，类的私有方法也是如此
 __sex = 0
 # 定义构造方法
 def __init__(self, name, site, sex):
 self.name = name
 self.site = site
 self.__sex = sex
 # 类方法
 def get_sex(self):
 return self.__sex
 def set_sex(self, sex):
 self.__sex = sex
# 单继承
class AndroidCoder(Developer):
 coder_id = 1024
 # 定义构造方法
 def __init__(self, name, site, sex, coder_id):
 # 调用父类构造方法
 # Developer.__init__(self, name, site, sex) # 老办法
 super(AndroidCoder, self).__init__(name, site, sex) # 采用新式
 self.coder_id = coder_id
 # 重写父类的方法
 def set_sex(self, sex):
 self.__sex = sex
 print('这是个秘密')
 def get_sex(self):
 return self.__sex
# 调用：
if __name__ == '__main__':
 # 单继承
 androidCoder = AndroidCoder('wxl', 'http://wuxiaolong.me/', 1, 520)
 print(androidCoder.set_sex(2))

# 多继承，B 继承 A，C 继承 B
class PythonCoder(AndroidCoder):
 # 定义构造方法
 def __init__(self, name, site, sex, coder_id):
 # 调用父类构造方法
 super(PythonCoder, self).__init__(name, site, sex, coder_id)
# 调用：
if __name__ == '__main__':
 pythonCoder = PythonCoder('wxl', 'http://wuxiaolong.me/', 1, 1024)
 print(androidCoder.get_sex())

class JavaCoder(object):
 java_id = 1
 # 定义构造方法
 def __init__(self, java_id):
 self.java_id = java_id
 print('来自JavaCoder')
class FullStackCoder(AndroidCoder, JavaCoder):
 # 定义构造方法
 def __init__(self, name, site, sex, coder_id):
 # 调用父类构造方法
 super(FullStackCoder, self).__init__(name, site, sex, coder_id)
 JavaCoder.__init__(self, coder_id) # 这里需要使用老办法
# 调用：
if __name__ == '__main__':
 fullStackCoder = FullStackCoder('wxl', 'http://wuxiaolong.me/', 1, 1024)

## 导入模块
import wxl_class
developer = wxl_class.Developer('wxl', 'http://wuxiaolong.me/', 1) # 实例变量
print(developer.site)

if __name__ == '__main__':
 pass

from wxl_def import hello1
m = hello1(666, 999)

import json
# Python 字典类型转换为 JSON 对象
python_data = {'id': 1024, 'name': 'wxl', 'site': 'http://wuxiaolong.me/'}
print(json.dumps(python_data)) # 打印：{"id": 1024, "name": "wxl", "site": "http://wuxiaolong.me/"}
# 将 JSON 对象转换为 Python 字典
json_data = '{"id": 1024, "name": "wxl", "site": "http://wuxiaolong.me/"}'
print(json.loads(json_data)) # 打印：{'id': 1024, 'name': 'wxl', 'site': 'http://wuxiaolong.me/'}

sudo easy_install pip

pip3 install PyMySQL

Collecting PyMySQL
 Using cached PyMySQL-0.7.11-py2.py3-none-any.whl
Installing collected packages: PyMySQL
Successfully installed PyMySQL-0.7.11

python -m pip install --upgrade pip

try:
 name = 'wxl'
 print(int(name))
except ValueError as e: # 所有的错误类型都继承自BaseException
 print(e)
finally:
 print('finally')

def write_file():
 try:
  f = open('/Users/wuxiaolong/Desktop/Python3Learn.txt', 'w') # 标示符'w'表示写
  f.write('Hello, Python')
 except BaseException as e:
  print(e)
 finally:
  if f:
   f.close()

def read_file():
 try:
  f = open('/Users/wuxiaolong/Desktop/Python3Learn.txt', 'r') # 标示符'r'表示读
  # print(f.read()) # read()会一次性读取文件的全部内容
  print(f.readlines()) # 每次读取一行内容，返回list
 except BaseException as e:
  print(e)
 finally:
  if f:
   f.close()

def read_byte_file():
 try:
  f = open('/Users/wuxiaolong/Desktop/Python3Learn.png', 'rb') # 标示符'rb'表示读
  print(f.read()) # read()会一次性读取文件的全部内容
  # print(f.readlines()) # 每次读取一行内容，返回list
 except BaseException as e:
  print(e)
 finally:
  if f:
   f.close()

f = open('/Users/wuxiaolong/Desktop/Python3Learn.txt', 'r', encoding='gbk', errors='ignore')