Python中如何判断文件是否存在？

import os

file_path = 'example.txt'
if os.path.exists(file_path):
    print(f"文件 {file_path} 存在")
else:
    print(f"文件 {file_path} 不存在")

import os

file_path = 'example.txt'
if os.path.isfile(file_path):
    print(f"文件 {file_path} 存在")
else:
    print(f"文件 {file_path} 不存在")

import os

file_path = 'example.txt'
abs_path = os.path.abspath(file_path)
norm_path = os.path.normpath(abs_path)

if os.path.isfile(norm_path):
    print(f"文件 {norm_path} 存在")
else:
    print(f"文件 {norm_path} 不存在")

import os

directory = '/path/to/directory'
files_in_directory = set(os.listdir(directory))

file_to_check = 'example.txt'
if file_to_check in files_in_directory:
    full_path = os.path.join(directory, file_to_check)
    if os.path.isfile(full_path):
        print(f"文件 {full_path} 存在")
    else:
        print(f"文件 {full_path} 存在但不是文件")
else:
    print(f"文件 {file_to_check} 不存在")

import os
import threading

def check_file(file_path):
    if os.path.isfile(file_path):
        print(f"文件 {file_path} 存在")
    else:
        print(f"文件 {file_path} 不存在")

file_paths = ['/path/to/file1.txt', '/path/to/file2.txt', '/path/to/file3.txt']

threads = []
for file_path in file_paths:
    thread = threading.Thread(target=check_file, args=(file_path,))
    threads.append(thread)
    thread.start()

for thread in threads:
    thread.join()