本帖最后由 武汉八期-陈汉清 于 2021-11-9 20:26 编辑
# if判断语句
# if语句单分支
# name = input("请输入你的用户名")
# if name =="666":
# print("用户名正确")
# else: #
# print("用户名错误")
# if多分支语句:持续进行判断
# a = 8
# b = 11
# c = 8
# if a > b:
# print("a大于b")
# elif c < a:
# print("a小于b")
# elif a == c:
# print("a等于c")
# dict1 = {"西藏":"王昭君","新疆":"迪丽热巴"}
# if dict1 == {"武汉":"大聪明"}:
# print(dict1)
# elif dict1 != {"武汉":"大聪明"}:
# dict1.setdefault("武汉","大聪明")
# print(dict1)
#
# dict1 = {"西藏":"王昭君","新疆":"迪丽热巴"}
# if dict1.__contains__("武汉"):
# print(dict1)
# else:
# dict1.setdefault("武汉","大聪明")
# print(dict1)
# 三目运算:三元表达式:简化if代码使用,只能支持if单分支语句
# 1,首先写的第一个判断想要执行的类容
# 2,if判断语句
# 3,else语句
# name = input("请输入你的用户名")
# print("正确") if name == "666" else print("错误")
# a = 5
# print("a等于大于5") if a >= 5 else print("a小于指定数")
# dict1 = {"西藏":"王昭君","新疆":"迪丽热巴"}
# print(dict1) if dict1.__contains__("武汉") else dict1.setdefault("武汉","大聪明")
# print(dict1)
# 通过输入函数输入用户名、先判断用户名是否正确、用户名正确
# 则 进行密码的判断如果用户名错误则提示:用户错误、请重新输入、密码错误
# 则提 示:您输入的密码有误、请重新输入密码输入正确则登录成功
# name = input("输入用户名")
# if name == "666":
# print("用户名正确")
# pwd = input("请输入密码")
# if pwd == "12345":
# print("密码正确")
# else:
# print("密码有误")
# else:
# print("用户错误")
# while循环语句
# while循环条件成立时进入循环
# while条件不成立时才能退出循环
# a = 100
# i = 1
# while a > i:
# i +=1
# print(i)
# 根据while循环求出1-100之间的和
# i = 1
# w = 0
# while i <=100:
# w += i
# i += 1
# print(w)
# #while求出1-100之间的奇数
# i = 1
# w = 0
# while i <=100:
# w += i
# i += 2
# print(w)
# #while求1-100之间的偶数
# i = 0
# w = 0
# while i <=100:
# w += i
# i += 2
# print(w)
# 求1-100之间的奇数和偶数
c = 0 #循环次数
h = 0 #求奇数
q = 0 #求偶数
# while c <=100:
# if c % 2 == 0:
# h += c
# else:
# q += c
# c += 1
# print(h,q)
# for 循环遍历:
#它可以遍历我序列当中的元素:str ,list ,tulpe ,dict ,set
# range():
# 从0开始输出,结束值不会被输出
# 第一个参数:是开始的值,默认为0
# 第二个参数:是结束的值,填写结束的值不会被输出
# 第三个参数:是步长值
# 奇数
# w = 0
# for i in range(1,101,2):
# w +=i
# print(w)
# 偶数
# w = 0
# for i in range(0,101,2):
# w +=i
# print(w)
# 奇数,偶数
# c = 0
# h = 0
# for i in range(0,101):
# if i % 2 == 0:
# c += i
# else:
# h += i
# print(c,h)
# break语句:条件达成,结束循环
# list1 = [1,2,3,4,5,6]
# for i in list1:
# if i == 3:
# break
# print(i)
# # continue语句:条件达成,跳出循环
# list1 = [1,2,3,4,5,6]
# for i in list1:
# if i == 3:
# continue
# print(i) |
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