Python按长度切割句子：实现超长文本按指定长度换行拆分

Got it, let's tackle this problem: you need to split a long sentence into multiple lines where each line's total length doesn't exceed a given limit, and you only want to split at spaces (so no broken words). Here's a practical, easy-to-follow function that gets the job done, plus an example using your sample input.

Solution Code #

def split_sentence_by_length(sentence, max_length):
    # Split the sentence into individual words
    words = sentence.split()
    lines = []
    current_line_words = []
    current_line_length = 0

    for word in words:
        word_len = len(word)
        # Calculate length needed to add this word (plus a space if line isn't empty)
        needed_length = current_line_length + word_len + (1 if current_line_words else 0)

        if needed_length <= max_length:
            # Word fits, add to current line
            current_line_words.append(word)
            current_line_length = needed_length
        else:
            # Word doesn't fit—finalize current line and start a new one
            lines.append(' '.join(current_line_words))
            current_line_words = [word]
            current_line_length = word_len

    # Don't forget to add the last line of words
    if current_line_words:
        lines.append(' '.join(current_line_words))
    
    return lines

# Test with your example
original = "This sentence is way too long."
max_char_limit = 15
split_lines = split_sentence_by_length(original, max_char_limit)

# Print the result
print("Original sentence:", original)
print(f"\nSplit into lines (max length {max_char_limit}):")
for idx, line in enumerate(split_lines, 1):
    print(f"Line {idx}: '{line}' (length: {len(line)})")

How It Works #

Let's break down what the function does:

• Split into Words: First, we split the input sentence into a list of words using spaces as separators—this ensures we only work with full words, no partial splits.
• Build Lines Iteratively: We loop through each word, checking if adding it to the current line (plus a space if the line isn't empty) would exceed the max length.
  • If it fits, we add the word to the current line and update the line's total length.
  • If it doesn't fit, we save the current line to our result list, then start a new line with the current word.
• Finalize Last Line: After the loop, we make sure to add the remaining words (the last line) to our result.

Example Output #

When you run the code with your sample input, you'll get this output:

Original sentence: This sentence is way too long.

Split into lines (max length 15):
Line 1: 'This sentence' (length: 13)
Line 2: 'is way too' (length: 10)
Line 3: 'long.' (length: 5)

Edge Case Note #

What if a single word is longer than the max length? The function will still add it as a single line (since we can't split at spaces). If you need to handle this scenario (like truncating the word or throwing a warning), you can add an extra check at the start of the loop to handle those cases.

内容的提问来源于stack exchange，提问作者helpme