Question

我试图编写将采用字符串和长度的python代码，并搜索字符串以告诉我哪个特定长度的子字符串出现次数最多，优先考虑第一个字符串是否有＆＃39;一个领带。

例如，@echo off setlocal enabledelayedexpansion cls set counter=0 for /f "delims=" %%A in (input.txt) do ( set line[!counter!]=%%A set /a counter+=1 ) set /a counter-=2 set LF=^ for /L %%A in (1,1,!counter!) do set sheet=!sheet!!line[%%A]!!LF! set /a counter+=1 for /L %%A in (!counter!,1,!counter!) do set sheet=!sheet!!line[%%A]! echo !sheet!>input.txt应返回@echo off setlocal enabledelayedexpansion cls :: findstr /n puts line numbers at the start of each line, which will allow us to preserve blank lines for /f "tokens=1 delims=:" %%A in ('findstr /n "^" input.txt') do set line_counter=%%A ::set /p preserves special characters <input.txt ( for /L %%A in (1,1,!line_counter!) do set /p line[%%A]= ) set /a line_counter-=1 set LF=^ :: Do NOT delete the two blank lines above this line. for /L %%A in (2,1,!line_counter!) do set sheet=!sheet!!line[%%A]!!LF! set /a line_counter+=1 for /L %%A in (!line_counter!,1,!line_counter!) do set sheet=!sheet!!line[%%A]! echo !sheet!>input.txt

我试过了：

"cadabra abra" 2

但似乎无法让它发挥作用。我知道我至少做错了一些事情，但我不确定是什么。这是我在Python中的第一个程序，但我认为我的问题可能更多的是算法而不是语法。

Answer 1

尝试使用内置方法，这样可以让您的生活更轻松：

>>> s = "cadabra abra"
>>> x = 2
>>> l = [s[i:i+x] for i in range(len(s)-x+1)]
>>> l
['ca', 'ad', 'da', 'ab', 'br', 'ra', 'a ', ' a', 'ab', 'br', 'ra']
>>> max(l, key=lambda m:s.count(m))
'ab'

编辑：

根据Stefan Pochmann评论更简单的语法：

>>> max(l, key=s.count)

Answer 2

import sys
from collections import OrderedDict

def main():
    inputstring = sys.argv[1]
    length = int(sys.argv[2])
    analyze(inputstring, length)

def analyze(inputstring, length):
    d = OrderedDict()
    for i in range(0, len(inputstring) - length + 1):    
        substring = inputstring[i:i+length]
        if substring in d:
            d[substring] += 1
        else:
            d[substring] = 1
    maxlength = max(d.values())
    for k,v in d.items():
        if v == maxlength:
            print(k)
            break

main()

Answer 3

非常好用于第一个Python程序的解决方案。在学习语言时，花一些时间阅读优秀的文档。它充满了例子和提示。

例如，标准库包括一个Counter类用于计算事物（显然）和一个OrderedDict类，它记住输入键的顺序。但文档中包含一个结合两者的例子来制作OrderedCounter，可以用来解决这个问题：

from collections import Counter, OrderedDict

class OrderedCounter(Counter, OrderedDict):
    pass

def analyze(s, n):
    substrings = (s[i:i+n] for i in range(len(s)-n+1))
    counts = OrderedCounter(substrings)
    return max(counts.keys(), key=counts.__getitem__)

analyze("cadabra abra", 2)

查找指定长度的大多数序列

3 个答案: