1. 循环的定义,反复做某事,具有明确的开始和结束. 2. 在Python中循环有while和for两种方式: While循环:1) 语法结构 >>> while 条件: ... 需要循环的语句 >>> i = 0 >>> while i < 3: ... print (i) ... i += 1 ... 0 1 2 For 循环: 1) 语法结构 >>> for i in range(2): #
Python中有while循环和for循环 下面以一个小例子来说明一下用法,用户输入一些数字,输出这些数字中的最大值和最小值 array = [5,4,3,1] for i in array: print(i) largest = None smallest = None while True: num = input("Enter a number: ") if num == "done" : break if len(num) < 1 : break #
--start-- for循环: for i in range(3): user_input = input("Your username:") passwd = int(input("Your password:")) if user_input == valid_user and passwd == valid_passwd: print("%s: Welcome to login!" % user_input) break elif use
# 1. print('1.我在学python 输出5遍') print('我在学python'*5) print('我在学python\n'*5) # 只能做单一重复 不能做线性 # 2.while print('2.while') # 用一个变量来控制循环次数(计数器) i = 1 while i <= 5: print('我在学python', i) i += 1 # 3.练习 1到100的累加 print('3.练习:1到100的累加') i = 1 total = 0 while i
假设有如下代码: for i in range(10): if i == 5: print 'found it! i = %s' % i else: print 'not found it ...' 你期望的结果是,当找到5时打印出: found it! i = 5 实际上打印出来的结果为: found it! i = 5 not found it ... 显然这不是我们期望的结果. 根据官方文档说法: >When the items are exhausted (which is immedi
>>> x = 100 >>> y = 10>>> x < y and x or y10>>> x if x > y else y100 if 语句: >>> x = 10>>> if x == 10:... print(x)... 10 >>> if x == 10:... print(x)... else:... print("x not 10!"
1. for i in range(10): print(i) 输出结果 F:\py\pyProject\venv\Scripts\python.exe F:/py/pyProject/venv/while.py 0 1 2 3 4 5 6 7 8 9 Process finished with exit code 0 2. age_of_oldboy = 56 for i in range(3): guess_age =int(input ("guess age:")) if gue
Python for循环可以遍历任何序列的项目,如一个列表或者一个字符串. 语法模式:for iterating_var in sequence: in 字面意思,从某个集合(列表等)里顺次取值 #遍历数字序列 the_count=[1,2,3,4,5] for number in the_count: print(f"This is count {number}") 输出结果: This is count 1This is count 2This is count 3This is