Python-for循环

l=['a','b','c']print(len(l))i=0while i<len(l):    print(l[i])    i+=1l=['a','b','c']for item in l: #item='a'    print(item)dic={'x':111,'y':222,'z':333}for k in dic: #k='x'    print(k,dic[k])while循环 VS for循环1.while循环：称之为条件循环，循环的次数取决于条件什么时候为Falsefor循环：称之为...循环，循环的次数取决于数据的包含的元素的个数2.for循环专门用来取值，在循环取值方面比while循环要强大，之后但凡遇到循环取值的场景，就应该用for循环 0   1    2l=['a','b','c']for i in range(3):    print(i,l[i])for+breaknames=['egon','kevin','alex','hulaoshi']for name in names:    if name == 'alex':break    print(name)for+continuenames=['egon','kevin','alex','hulaoshi']for name in names:    if name == 'alex':continue    print(name)for+elsenames=['egon','kevin','alex','hulaoshi']for name in names:    # if name == 'alex':break    print(name)else:    print('=====>')for循环嵌套for i in range(3): #i=2    for j in range(2): #j=1        print(i,j) #2，1'''外层循环第一次：i=0    内层循环        0，0        0，1外层循环第二次：i=1    内层循环        1，0        1，1外层循环第三次: i=2    内层循环        2,0        2,1'''print(' ',end='')print('bbbbb',end='')