如何在Python中不使用正则表达式实现大小写不敏感的用户输入文本匹配

First, let's break down what was wrong with your original code:

• You reused x as the loop variable, which overwrote your original search term (bad practice that breaks matching logic).
• The condition x.islower() or x.isupper() or x.capitalize() doesn't check for matches at all. x.capitalize() returns a non-empty string, which is always "truthy" in Python—so this condition just returned every word split from the text.

Here's the corrected code that does exactly what you need: finds all original words in the text that contain your search term (case-insensitive, no regex required):

# Get and clean the user's search input
search_term = self.lineEditSearch.text().strip()

# Handle empty input to avoid unexpected results
if not search_term:
    self.varStr = []
    print("No search term entered.")
    return

# Read the file content
text_content = self.ReadingFileContent(Item)

# Split content into words (handles multiple spaces automatically)
all_words = text_content.split()

# Collect original words where search term is a substring (case-insensitive)
self.varStr = [word for word in all_words if search_term.lower() in word.lower()]

# Print the result to verify
print(f"Matching words: {self.varStr}")

How this works: #

• Case insensitivity: By converting both the search term and each word to lowercase with .lower(), we eliminate case differences entirely.
• Substring match: The in operator checks if the lowercase search term exists anywhere within the lowercase word (so "charl" will match "Charles", "charles", or "CHARLES").
• Preserves original words: We add the original word (with its original case and punctuation) to self.varStr, not the lowercase version.

Example Output: #

If your text contains "Les hiboux Charles Baudelaire ... Charles Pierre Baudelaire" and the user inputs "charl", self.varStr will be:

["Charles", "Charles"]

Optional: Handling Punctuation #

If you want to ignore punctuation attached to words (like "établiront." or "méditent,"), you can modify the code to strip common punctuation first while keeping the original word in results:

import string

# ... (previous code)

# Strip punctuation from each word before checking, but retain original word in output
self.varStr = [
    word for word in all_words 
    if search_term.lower() in word.strip(string.punctuation).lower()
]

This way, searching for "etabliront" will match "établiront." since we strip the period before checking, but the result still includes the original word "établiront.".

内容的提问来源于stack exchange，提问作者Propy Propy