使用Python 2.7.1中的itertools，yield和iter()生成带有滑动窗口的字符串列表? [英] Generate a list of strings with a sliding window using itertools, yield, and iter() in Python 2.7.1?

问题描述

我正在尝试在Python中生成一个滑动窗口函数.我想出了如何做到这一点，但并非所有功能都在其中. itertools，yield和iter()对我来说是全新的.

I'm trying to generate a sliding window function in Python. I figured out how to do it but not all inside the function. itertools, yield, and iter() are entirely new to me.

我想输入

a='abcdefg'
b=window(a,3)
print b
['abc','bcd','cde','def','efg']

我工作的方式是

def window(fseq, window_size=5):
    import itertools
    tentative=[]
    final=[]
    iteration=iter(fseq)
    value=tuple(itertools.islice(iteration,window_size))
    if len(value) == window_size:
        yield value
    for element in iteration:
        value = value[1:] + (element,)
        yield value

a='abcdefg'
result=window(a)
list1=[]
for k in result:
    list1.append(k)
list2=[]   
for j in list1:
    tentative=''.join(j)
    list2.append(tentative)
print list2

基本上我困惑的是如何在函数内部使用函数的最终值?

basically what im confused about is how to use the final value of the function inside the function?

这是我的函数代码

def window(fseq, window_size=5):
    import itertools
    tentative=[]
    final=[]
    iteration=iter(fseq)
    value=tuple(itertools.islice(iteration,window_size))
    if len(value) == window_size:
        yield value
    for element in iteration:
        value = value[1:] + (element,)
        yield value
    for k in value:
        tentative.append(k)
    for j in tentative:
        tentative_string=''.join(j)
        final.append(tentative_string)
    return final



seq='abcdefg'
uence=window(seq)
print uence

我希望它返回加入的列表，但是当我按下运行它时，它说:您的程序 * 'return'并在生成器内部带有参数时出错"

i want it to return the joined list but when i press run it, it says "There's an error in your program * 'return' with argument inside generator"

我真的很困惑. . .

I'm really confused . . .

推荐答案

您是说要这样做? :

a='abcdefg'
b = [a[i:i+3] for i in xrange(len(a)-2)]
print b
['abc', 'bcd', 'cde', 'def', 'efg']

这篇关于使用Python 2.7.1中的itertools，yield和iter()生成带有滑动窗口的字符串列表?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！