如何连接以字母开头的行？

import re

def connect_lines_starting_with_letter(text):
    lines = text.split('\n')
    connected_lines = []
    pattern = r'^[A-Za-z].*'
    
    for line in lines:
        if re.match(pattern, line):
            connected_lines.append(line)
    
    result = '\n'.join(connected_lines)
    return result

# 示例用法
text = '''
This is a sample text.
A line starting with a letter.
Another line starting with a letter.
1234 Not a letter.
Yet another line starting with a letter.
'''

connected_text = connect_lines_starting_with_letter(text)
print(connected_text)

A line starting with a letter.
Another line starting with a letter.
Yet another line starting with a letter.