python enumerate 函数用法

enumerate字典上是枚举、列举的意思。

C语言中关键字enum也是enumerate的缩写。

python中enumerate方法，返回一个enumerate类型。参数一般是可以遍历的的东西，比如列表，字符串什么的。

python文档中是这么说的：

enumerate(sequence, [start=0])

Return an enumerate object. sequence must be a sequence, an iterator, or some other object which sup-

ports iteration. The next() method of the iterator returned by enumerate() returns a tuple containing

a count (from start which defaults to 0) and the corresponding value obtained from iterating over iter-

able. enumerate() is useful for obtaining an indexed series: (0, seq[0]), (1, seq[1]), (2,

seq[2]), ....

For example:

>>> for i, season in enumerate([’Spring’, ’Summer’, ’Fall’, ’Winter’]):

...

print i, season

0 Spring

1 Summer

2 Fall

3 Winter

我试了一下，如果那句循环改成

for season in [’Spring’, ’Summer’, ’Fall’, ’Winter’]：

其实也是可以的，只是enumerate会返回一个有索引的东西，就是前边的那个i，那个i从0开始，每一项加一。

时间： 2024-12-29 16:28:41

python enumerate 函数用法的相关文章

python enumerate函数用法

enumerate函数用于遍历序列中的元素以及它们的下标 i = 0 seq = ['one', 'two', 'three'] for element in seq: print i, seq[i] i += 1 #0 one #1 two #2 three print '============' seq = ['one', 'two', 'three'] for i, element in enumerate(seq): print i, seq[i] print '===========

python之函数用法capitalize()

# -*- coding: utf-8 -*- #python 27 #xiaodeng #python之函数用法capitalize() #capitalize() #说明:将字符串的第一个字母变成大写,其他字母变小写. ''' capitalize(...) S.capitalize() -> string Return a copy of the string S with only its first character capitalized. ''' #案例 str='xiaoden

python之函数用法setdefault()

# -*- coding: utf-8 -*- #python 27 #xiaodeng #python之函数用法setdefault() #D.get(k,d) #说明:k在D中,则返回 D[K],如果k不在D中,则返回d值 #D.get(k,d), also set D[k]=d if k not in D ''' >>> help(dict.setdefault) Help on built-in function setdefault: setdefault(...) D.set

python之函数用法islower()

# -*- coding: utf-8 -*- #python 27 #xiaodeng #python之函数用法islower() #http://www.runoob.com/python/att-string-islower.html #islower() #说明:检测字符串是否都由小写字母组成 str = "THIS is string example....wow!!!" print str.islower()#False str = "this is string

python之函数用法xrange()

# -*- coding: utf-8 -*- #python 27 #xiaodeng #python之函数用法xrange() #xrange() #说明:返回一个生成器 #xrange做循环的性能比range好,尤其是返回很大的时候.除非要返回一个列表,则用range. ''' class xrange(object) | xrange(stop) -> xrange object | xrange(start, stop[, step]) -> xrange object | | Li

python之函数用法startswith()

# -*- coding: utf-8 -*- #python 27 #xiaodeng #python之函数用法startswith() #http://www.runoob.com/python/att-string-startswith.html #startswith() #说明:返回布尔值,用于检查字符串是否是以指定子字符串开头,如果是则返回 True,否则返回 False. ''' startswith(...) S.startswith(prefix[, start[, end]]

python之函数用法globals()

# -*- coding: utf-8 -*- #python 27 #xiaodeng #python之函数用法globals() #globals() #说明:在当前作用域下,查看全局变量 ''' globals(...) globals() -> dictionary Return the dictionary containing the current scope's global variables. ''' #案例 b='xiaodeng' print globals#<buil

python之函数用法setattr

# -*- coding: utf-8 -*- #python 27 #xiaodeng #python之函数用法__setattr__ #http://www.cnblogs.com/hongfei/p/3858256.html #用__setattr__函数重构方法 class Fruit(): def __init__(self,color,price): self.__color = color self.__price = price def __setattr__(self,name

python之函数用法get()

# -*- coding: utf-8 -*- #python 27 #xiaodeng #python之函数用法get() #http://www.runoob.com/python/att-dictionary-get.html #dict.get(key, default=None) #说明:返回指定键的值,如果值不在字典中返回默认值. #key:要查找的键 #default:如果指定键的值不存在时,返回该默认值值 ''' >>> help(d.get) Help on built