Python enumerate()

enumerate() 函数用于将一个可遍历的数据对象(如列表、元组或字符串)组合为一个索引序列,同时列出数据和数据下标,一般用在 for 循环当中。

Python 2.3. 以上版本可用,2.6 添加 start 参数。

Syntax:

enumerate(iterable, start=0)

Parameters:
Iterable: any object that supports iteration
Start: the index value from which the counter is 
              to be started, by default it is 0 

参数

  • iterable -- 一个序列、迭代器或其他支持迭代对象。
  • start -- 下标起始位置。
# Python program to illustrate
# enumerate function
l1 = ["eat","sleep","repeat"]
s1 = "geek"
  
# creating enumerate objects
obj1 = enumerate(l1)
obj2 = enumerate(s1)
  
print "Return type:",type(obj1)
print list(enumerate(l1))
  
# changing start index to 2 from 0
print list(enumerate(s1,2))

Output:

Return type: < type 'enumerate' >
[(0, 'eat'), (1, 'sleep'), (2, 'repeat')]
[(2, 'g'), (3, 'e'), (4, 'e'), (5, 'k')]


# Python program to illustrate
# enumerate function in loops
l1 = ["eat","sleep","repeat"]
  
# printing the tuples in object directly
for ele in enumerate(l1):
    print ele
print 
# changing index and printing separately
for count,ele in enumerate(l1,100):
    print count,ele

Output:

(0, 'eat')
(1, 'sleep')
(2, 'repeat')

100 eat
101 sleep
102 repeat

 

posted @ 2020-09-16 19:06  XXXSANS  阅读(172)  评论(0编辑  收藏  举报