1. range(object):

"""     range(stop) -> range object     range(start, stop[, step]) -> range object     Return an object that produces a sequence of integers from start (inclusive)     to stop (exclusive) by step.  range(i, j) produces i, i+1, i+2, ..., j-1.     start defaults to 0, and stop is omitted!  range(4) produces 0, 1, 2, 3.     These are exactly the valid indices for a list of 4 elements.     When step is given, it specifies the increment (or decrement).

a = 'TjkdFGklfsaYYY'for i in range(0,len(a)): #range(0,len(a))效果一样    print(i,a[i])___________________0 T1 j2 k3 d4 F5 G6 k7 l8 f9 s10 a11 Y12 Y13 Y

　加入range()步长

a = input(".....")for i in range(0,len(a)):    print(i,a[i])————————.....djklajs k0 d1 j2 k3 l4 a5 j6 s7  8 k

a = input(".....")for i in range(0,len(a),3):    print(i,a[i])______________.....jdkfskjkfdsl0 j3 f6 j9 d

　　

　　

 

2.  len(*args, **kwargs): # real signature unknown

""" Return the number of items in a container.

a1 = 'TjkdFGklfsaYYY'a2 = [1,2,3,4,5,'jflkas']b1 = len(a1)b2 = len(a2)print(b1,b2)------------------14 6

3. 脚标

a = 'TjkdFGklfsaYYY'index = 0while index < len(a):    b = a[index]    print(b)    index += 1____________________TjkdFGklfsaYYY

　　

a1 = 'TjkdFGklfsaYYY'a2 = [1,2,3,4,5,'jflkas']print(a1[2], a2[3])————————————k 4