Python实现按首字母分类查找与字典优化方案

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发布时间：2026-10-13| 5人浏览过

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本文介绍Python中按首字母分类查找英文词汇的实现方法。首先通过遍历列表进行基础匹配，随后利用字典结构优化存储与查询效率。代码展示了如何构建字母索引并实现快速检索，适用于类似通讯簿的快速查找场景，帮助开发者掌握字符串处理与数据结构应用。

Python按首字母分类查找与字典优化方案

本文分享一段Python代码，演示如何实现按首字母分类查找的功能，供读者参考。

具体需求如下：

1. 自行收集一组英文词汇，并将其存储于容器类数据结构中。 2. 根据这些英文词汇的首字母进行分类，实现类似手机通讯录中的快速查找功能。 3. 接收用户输入的字母，并找出所有以该字母开头的单词。


#coding=utf-8
lexicons=["the","be","of","and","A","to","in","he","have","it","that","for","they","I","with","as","not","on","she","at","by","this","we","you","do","but","from","or","which","one","would","all","will","there","say","who","make","when","can"]
while True:
 startLetter=raw_input("输入一个字母，列出所有以此字母开头的单词:")
 if len(startLetter)!=1:
 print "必须是一个字母"
 else:
 reLexicons=[] #结果列表
 for x in xrange(len(lexicons)):
  lexicon=lexicons[x]
  if lexicon[0].lower()==startLetter.lower():#都转为小写后比较 开头字母不区分大小写
  reLexicons.append(lexicon)
 if len(reLexicons)==0:
  print "没有结果"
 else:
  for x in xrange(len(reLexicons)):
  print reLexicons[x]

前文示例未涉及第二步的分类存储，以下代码使用字典结构来解决该步骤。


#coding=utf-8
'''
边遍历，边构造 key value 
'''
lexicons=["the","be","of","and","A","to","in","he","have","it","that","for","they","I","with","as","not","on","she","at","by","this","we","you","do","but","from","or","which","one","would","all","will","there","say","who","make","when","can"]
lexiconDict={}
#分类 保存字典中
lexiconLen=len(lexicons)
for x in xrange(len(lexicons)):
 lexicon=lexicons[x]
 startLetter=lexicon[0]
 dictLexicons=lexiconDict.get(startLetter,[])
  #空列表说明没有Key 则添加Key 否则追加Key对应的Value
 if len(dictLexicons)==0:
 lexiconDict[startLetter]=[lexicons[x]]
 else:
 dictLexicons.append(lexicons[x])
while True:
 startLetter=raw_input("输入一个字母，列出所有以此字母开头的单词:")
 if len(startLetter)!=1:
 print "必须是一个字母"
 else:
 lexicons=lexiconDict.get(startLetter.lower(),[])
 if len(lexicons)==0:
  print "没有结果"
 else:
  for x in lexicons:
  print x

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