Python的 - 分裂列表包含字符串和整数

Question

myList = [ 4,'a', 'b', 'c', 1 'd', 3] 

如何将此列表拆分成一个包含字符串和其他包含优雅/ Python的方式整数两个列表？

输出：

myStrList = [ 'a', 'b', 'c', 'd' ] 

myIntList = [ 4, 1, 3 ] 

注：没有执行这样的列表，就是想如何找到一个优雅的答案（有没有？）这样的问题。

Answer 1

正如其他人在评论中提到的那样，你应该真的开始考虑如何摆脱列表中包含非同类数据的列表。但是，如果真的无法做，我会使用一个defaultdict：

from collections import defaultdict 
d = defaultdict(list) 
for x in myList: 
    d[type(x)].append(x) 

print d[int] 
print d[str] 

Answer 2

您可以使用列表理解： -

>>> myList = [ 4,'a', 'b', 'c', 1, 'd', 3] 
>>> myIntList = [x for x in myList if isinstance(x, int)] 
>>> myIntList 
[4, 1, 3] 
>>> myStrList = [x for x in myList if isinstance(x, str)] 
>>> myStrList 
['a', 'b', 'c', 'd'] 

Answer 3

def filter_by_type(list_to_test, type_of): 
    return [n for n in list_to_test if isinstance(n, type_of)] 

myList = [ 4,'a', 'b', 'c', 1, 'd', 3] 
nums = filter_by_type(myList,int) 
strs = filter_by_type(myList,str) 
print nums, strs 

>>>[4, 1, 3] ['a', 'b', 'c', 'd'] 

Answer 4

拆分列表按照类型在原单列表

myList = [ 4,'a', 'b', 'c', 1, 'd', 3] 
types = set([type(item) for item in myList]) 
ret = {} 
for typeT in set(types): 
    ret[typeT] = [item for item in myList if type(item) == typeT] 

>>> ret 
{<type 'str'>: ['a', 'b', 'c', 'd'], <type 'int'>: [4, 1, 3]} 

Answer 5

我要回答一个Python FAQ“怎么做来概括这个线程发现你写了一个方法，它可以以任何顺序，范围很窄的类型来引用参数？“

假设所有参数左到右的顺序并不重要，试试这个（基于@mgilson的答案）：

def partition_by_type(args, *types): 
    d = defaultdict(list) 

    for x in args: 
     d[type(x)].append(x) 

    return [ d[t] for t in types ] 

def cook(*args): 
    commands, ranges = partition_by_type(args, str, range) 

    for range in ranges: 
     for command in commands: 
      blah blah blah... 

现在，您可以拨打cook('string', 'string', range(..), range(..), range(..))。参数顺序在其类型内是稳定的。

# TODO make the strings collect the ranges, preserving order 

Answer 6

import strings; 
num=strings.digits; 
str=strings.letters; 
num_list=list() 
str_list=list() 
for i in myList: 
    if i in num: 
     num_list.append(int(i)) 
    else: 
     str_list.append(i)