转自：https://zhuanlan.zhihu.com/p/168608305

    1. # Python计算字符串或文件的MD5/SHA值
    2. import time
    3. import os
    4. import hashlib
    7. # 计算文件的MD5/SHA值
    8. def file(path, algorithm):
    9.     global start, end  # 声明全局变量
    10.     start = time.time()  # 获取当前时间，用于记录计算过程的耗时
    11.     size = os.path.getsize(path)  # 获取文件大小，单位是字节（byte）
    12.     with open(path, 'rb') as f:  # 以二进制模式读取文件
    13.         while size >= 1024 * 1024:  # 当文件大于1MB时将文件分块读取
    14.             algorithm.update(f.read(1024 * 1024))
    15.             size -= 1024 * 1024
    16.         algorithm.update(f.read())
    17.     end = time.time()  # 获取计算结束后的时间
    18.     print()
    19.     print(algorithm.hexdigest())  # 输出计算结果
    22. # 计算字符串的MD5/SHA值
    23. def str(text, algorithm):
    24.     global start, end
    25.     start = time.time()
    26.     algorithm.update(text.encode(encoding='UTF-8'))
    27.     end = time.time()
    28.     print()
    29.     print(algorithm.hexdigest())
    31. print('https://blog.zeruns.tech')
    32. print('1.MD5  2.SHA1 3.SHA224 4.SHA256 5.SHA384 6.SHA512')
    33. flag1 = int(input('请选择算法：'))
    34. print('\n1.文件 2.字符串')
    35. flag2 = int(input('请选择要计算的是文件还是字符串：'))
    36. if flag2 == 1:
    37.     path = input('\n请输入要计算的文件的目录（若跟脚本同目录直接输入文件名即可）：')
    38.     if flag1 == 1:
    39.         file(path, hashlib.md5())
    40.     elif flag1 == 2:
    41.         file(path, hashlib.sha1())
    42.     elif flag1 == 3:
    43.         file(path, hashlib.sha224())
    44.     elif flag1 == 4:
    45.         file(path, hashlib.sha256())
    46.     elif flag1 == 5:
    47.         file(path, hashlib.sha384())
    48.     elif flag1 == 6:
    49.         file(path, hashlib.sha512())
    50. elif flag2 == 2:
    51.     text = input('\n请输入要加密的字符串：')
    52.     if flag1 == 1:
    53.         str(text, hashlib.md5())
    54.     elif flag1 == 2:
    55.         str(text, hashlib.sha1())
    56.     elif flag1 == 3:
    57.         str(text, hashlib.sha224())
    58.     elif flag1 == 4:
    59.         str(text, hashlib.sha256())
    60.     elif flag1 == 5:
    61.         str(text, hashlib.sha384())
    62.     elif flag1 == 6:
    63.         str(text, hashlib.sha512())
    65. print("\n计算耗时: %s seconds" % (end - start))