filename = "example.txt"
line_count = 0
with open(filename, "r") as file:
    for line in file:
        line_count += 1
print(f"The file 'example' has {line_count} lines.")

其中example.txt文件内容如下：

      My Favorite Animal
Once upon a time, I had a pet dog named Max. Max was the most obedient dog I knew.
We played fetch in the park, went on long walks in the woods, and even took naps together on lazy afternoons.