只会打印空白列表

Question

我正在遍历.txt文件并尝试在其中找到回文短语，但是当我运行此文件时，它只会打印一个空列表。

file = open("dictionary.txt", "r")# Load digital dictionary as a list of words

def find_palingram():
    palingram_list = [] # Start an empty list to hold palingrams
    for word in file: # For word in list
        word = word.split()
        end = len(word) # Get length of word
        rev_word = word[::-1]
        if(end > 1):#If Length > 1
            for i in range(end): # Loop through the letters in the word
                """If reversed word fragment at front of word is in word list and letters after form a
                palindromic sequence"""
                if(word[i:] == rev_word[:end-i] and rev_word[end-i:] in file):
                    palingram_list.append(word, rev_word[end-i:])#Append word and reversed word to palingram list
                """If reversed word fragment at end of word is in word list and letters
                before form a palindromic sequence"""
                if(word[:i] == rev_word[end-i:] and rev_word[:end-i] in file):
                    palingram_list.append(rev_word[:end-i], word) # Append reversed word and word to palingram list
    return palingram_list
    file.close()
# Sort palingram list alphabetically
palingram = find_palingram()
palingram_sorted = sorted(palingram)
print(palingram_sorted)
print(file.read())

Answer 1

检查单词是否为回文真的很容易：

word[::-1] == word

或者，如果您包括palindrom的定义，例如，Eve：

word_lower = word.lower()
word_lower[::-1] == word_lower 

因此，您的程序可以简化为：

def find_palindroms(text):
    palindrom_list = []
    for line in text:
        for word in line.rstrip().split():
            word_lower = word.lower() # might be unnecessary
            if word_lower[::-1] == word_lower:
                palindrom_list.append(word)
    return palindrom_list 

with open("dictionary.txt", "r") as file:
    print(find_palindroms(file))

Answer 2

您应该在函数之间传递文件。此外，file.close（）将关闭文件，并且由于其在函数中而将永远不会执行。