Python-Day-100 笔记

from module1 import foo
from module2 import foo
foo()

def foo():
    pass
# __name__是Python中一个隐含的变量它代表了模块的名字
# 只有被Python解释器直接执行的模块的名字才是__main__
if __name__ == '__main__':
    print('call foo()')
    foo()

s1 = r'\n\\hello, world!\\\n'
print(s1) # \n\\hello, world!\\\n

a,b = 5,10
print('%d * %d = %d' % (a, b, a * b))
print('{0} * {1} = {2}'.format(a, b, a * b))
print(f'{a} * {b} = {a * b}')

list = [1,2,3,4,5,6]
//通过下标访问
for index in range(len(list)):
	print(list[index])
//遍历元素访问
for elem in list:
	print(elem)
//使用enumerate()处理获得元素及其下标
for index, elem in enumerate(list1): 
	print(index, elem)

//用列表的生成表达式语法创建列表容器
//表达式生成的容器里面元素已经准备就绪，所以会耗费较多内存空间
f1 = [x ** 2 for x in range(1, 1000)]

//下面的代码创建的不是一个列表而是一个生成器对象
//生成器会在使用时，经过运算获取数据，不占用额外空间，但是消耗时间
f2 = (x ** 2 for x in range(1, 1000))

def fib(n):
    a, b = 0, 1
    for _ in range(n):
        a, b = b, a + b
        yield a


def main():
    for val in fib(20):
        print(val)


if __name__ == '__main__':
    main()

set1 = {1, 2, 3, 3, 3, 2}

# 集合的交集、并集、差集、对称差运算
print(set1 & set2)
# print(set1.intersection(set2))
print(set1 | set2)
# print(set1.union(set2))
print(set1 - set2)
# print(set1.difference(set2))
print(set1 ^ set2)
# print(set1.symmetric_difference(set2))
# 判断子集和超集
print(set2 <= set1)
# print(set2.issubset(set1))
print(set3 <= set1)
# print(set3.issubset(set1))
print(set1 >= set2)
# print(set1.issuperset(set2))
print(set1 >= set3)
# print(set1.issuperset(set3))

dic1={'筑基丹': 1100, '元灵精华': 900, '磐龙宝剑': 11000}

# 创建字典的构造器语法
items1 = dict(one=1, two=2, three=3, four=4)

# 通过zip函数将两个序列压成字典
items2 = dict(zip(['a', 'b', 'c'], '123'))

# 对字典中所有键值对进行遍历
for key in dic1:
    print(f'{key}: {dic1[key]}')
	
# get方法也是通过键获取对应的值但是可以设置默认值
print(scores.get('神农鼎', 60))

class Student(object):

    # __init__是一个特殊方法用于在创建对象时进行初始化操作
    # 通过这个方法我们可以为学生对象绑定name和age两个属性
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def study(self, course_name):
        print('%s正在学习%s.' % (self.name, course_name))
		
def main():
	stu1 = Student('大卫',18)
	stu1.study()

class Test:

    def __init__(self, foo):
        self.__foo = foo

    def __bar(self):
        print(self.__foo)
        print('__bar')
		
def main():
    test = Test('hello')
    test._Test__bar()
    print(test._Test__foo)

if __name__ == "__main__":
    main()

class Person(object):
	def __init__(self,name,age):
		self.name = name
		self.age = age
	@property
	def name(self):
		return self.name
	
	@property
	def age(self):
		return self.age
	
	@age.setter
	def age(self,age):
		self.age = age

#没有定义name的setter方法，如果访问的话会报AttributeError: can't set attribute错误

class Person(object):
	
	__slots__ = ('_name', '_age', '_gender')
	
	def __init__(self,name,age):
		self.name = name
		self.age = age
	@property
	def name(self):
		return self.name
	
	@property
	def age(self):
		return self.age
	
	@age.setter
	def age(self,age):
		self.age = age

#如果添加或设置不在__slots__包含的属性，如'_is_man'则会报错AttributeError: 'Person' object has no attribute '_is_man'

class Triangle(object):

    def __init__(self, a, b, c):
        self._a = a
        self._b = b
        self._c = c

    @staticmethod
    def is_valid(a, b, c):
        return a + b > c and b + c > a and a + c > b

def main():
	#静态方法
	a,b,c = 6,8,10
	if Triangle.is_valid(a, b, c):
		print("构成三角形")

if __name == '__main__':
	main()

class Clock(object):
	
    """数字时钟"""

	def __init__(self, hour=0, minute=0, second=0):
		self._hour = hour
		self._minute = minute
		self._second = second
		
	@classmethod
	def now(cls):
		ctime = localtime(time())
		return cls(ctime.tm_hour, ctime.tm_min, ctime.tm_sec)
	
	def show(self):
        """显示时间"""
        return '%02d:%02d:%02d' % \
               (self._hour, self._minute, self._second)

	
def main():
	clock = Clock.now()
	clock.show()


if __name == '__main__':
	main()

class Person(object):
	def __init__(self, name, age):
		self._name = name
		self._age = age
		
	"""
	省略setter和getter方法
	"""
class Student(Person):
	
	def __init__(self, name, age, grade):		
		super().__init__(name, age)#调用父类的初始化方法
		self._grade = grade

from abc import ABCMeta, abstractmethod


class Pet(object, metaclass=ABCMeta):
	"""宠物"""

	def __init__(self, nickname):
		self._nickname = nickname

	@abstractmethod
	def make_voice(self):
		"""发出声音"""
		pass
	
class Dog(Pet):
	def make_voice(self):
		print('%s: 汪汪汪...' % self._nickname)

class Cat(Pet):
	def make_voice(self):
		print('%s: 喵...喵...' % self._nickname)

def main():
    f = None
    try:
        f = open('致橡树.txt', 'r', encoding='utf-8')
        print(f.read())
    except FileNotFoundError:
        print('无法打开指定的文件!')
    except LookupError:
        print('指定了未知的编码!')
    except UnicodeDecodeError:
        print('读取文件时解码错误!')
    finally:
        if f:
            f.close()


if __name__ == '__main__':
    main()

   with open('致橡树.txt', 'r', encoding='utf-8') as f:
   	print(f.read())

with open('致橡树.txt', 'r', encoding='utf-8') as f:
	print(f.read())
	
ith open('致橡树.txt', mode='r') as f:
	for line in f:
		print(line, end='')
		
with open('致橡树.txt') as f:
	lines = f.readlines()
	print(lines)

mydict = {
  "tieba":{
    "type": "image",
    "container": [
      { "icon": "< img src =\"emoji/tieba/呵呵.png\">", "text": "呵呵" },
      { "icon": "< img src =\"emoji/tieba/哈哈.png\">", "text": "哈哈" }
	]
    }
		}
with open('data.json', 'w', encoding='utf-8') as fs:
		json.dump(mydict, fs)