如何提取文本文件中数字前的单词？Python代码实现求助

Let’s walk through a practical, Python-based approach to solve your problem—we’ll safely read your text files, filter lines containing your target content, and pull out the words immediately preceding numeric sequences.

Step-by-Step Breakdown #

1. Safe File Handling with Context Managers #

Instead of using f = open(FILENAME, 'r') directly, we’ll use a with statement. This automatically closes the file after processing, preventing resource leaks and making your code more robust.

2. Filter Lines with Specific Content #

First, define the string you want to target (like "Error"), then skip any lines that don’t include this content to focus only on relevant lines.

3. Regular Expressions for Pattern Matching #

We’ll use regex to identify words followed by numbers. The pattern r'(\w+)\s+(\d+)' captures any word (letters/underscores) that comes right before whitespace and one or more digits. Using re.findall() lets us grab all such pairs in a single line.

Full Code Example #

import re

FILENAME = "your_file.txt"  # Replace with your actual file path
TARGET_CONTENT = "Error"    # Replace with your specific content to locate lines

def extract_words_before_numbers():
    with open(FILENAME, 'r') as f:
        for line in f:
            cleaned_line = line.strip()
            # Skip lines that don't contain our target content
            if TARGET_CONTENT not in cleaned_line:
                continue
            # Find all word-number pairs in the line
            matches = re.findall(r'(\w+)\s+(\d+)', cleaned_line)
            # Extract just the words from each matched pair
            target_words = [match[0] for match in matches]
            print(f"Words found in line: {target_words}")

if __name__ == "__main__":
    extract_words_before_numbers()

Testing with Your Sample Inputs #

Let’s see how this works with your example lines:

Sample 1 Line: #

Error you can find the Error in Section Nose 546516547 in Lower Part 211547
Output: ['Nose', 'Part']

Sample 2 Line: #

Error the file break at you knee 3215467 in the element 51423165
Output: ['knee', 'element']

Customization Tips #

• If your "words" include special characters (like hyphens or apostrophes), adjust the regex to r'([\w-]+)\s+(\d+)' to include hyphens, or expand the character set as needed.
• To match only specific number lengths (e.g., 7-9 digits), modify the digit part: r'(\w+)\s+(\d{7,9})'.
• Instead of printing results, you can collect them in a list or write them to a new file for later use.

Quick Notes #

• Don’t forget to import the re module—it’s required for regex operations.
• The strip() method removes leading/trailing whitespace from lines, ensuring cleaner pattern matching.

内容的提问来源于stack exchange，提问作者classic