PYTHON压平嵌套列表的简单实现
list 是 Python 中使用最频繁的数据类型, 标准库里面有丰富的函数可以使用。
不过，如果把多维列表转换成一维列表(不知道这种需求多不多),还真不容易找到好用的函数，
要知道Ruby、Mathematica、Groovy中可是有flatten的啊。
如果列表是维度少的、规则的，还算好办
例如:
li=[[1,2],[3,4],[5,6]] print [j for i in li for j in i] #or from itertools import chain print list(chain(*li)) #or a=[[1,2],[3,4],[5,6]] t=[] [t.extend(i) for i in a] print t #or print sum(li,[])
对于复杂一些的，如：li=[1,[2],[[3]],[[4,[5],6]]]，上面的方法就不好使了，得换个方法了，
从结构上看像是树状的，很容易联想到了目录的遍历，于是就有了下面的做法：
def flat(tree):
res = []
for i in tree:
if isinstance(i, list):
res.extend(flat(i))
else:
res.append(i)
return res另一种思路，嵌套列表无非就是有很多成对的方括号，一维的列表只有一对，把中间的去掉就行了，转换为字符串就好办了
def flatten(seq):
s=str(seq).replace('[', '').replace(']', '') #当然也可以用正则
return [eval(x) for x in s.split(',') if x.strip()]不过，这种做法对于列表中出现包含"["或"]"的字符串时就无能为力了，需要改进.
其他方法：
国外某论坛上见到的，同样是递归，一行搞定
flat=lambda L: sum(map(flat,L),[]) if isinstance(L,list) else [L]
下面这个方法用到Tkinter模块，在邮件列表看到的方法。估计很多同学还不知道它能办到吧，也算是python自带。注意,windows版的python都自带Tkinter模块的，linux默认则没有
from Tkinter import _flatten li=reduce(lambda *x:list(x),range(2,6),[1]) print li print _flatten(li) #Out: #[[[[[1], 2], 3], 4], 5] #(1, 2, 3, 4, 5) #对元组同样适用
还有一些第三方模块提供这样的功能，如sympy、numpy、pipe等
对于嵌套的元组，无需多说了吧，只需稍加改动就可以了
以上这篇PYTHON压平嵌套列表的简单实现就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持脚本之家。
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