base 64 编码是使用弧度 64 将二进制编码为 ASCII 字符串格式的通用方案。base64 模块是标准库的一部分，这意味着它与 Python 一起安装。了解字节和字符串对本主题至关重要，可以在此处复习。本主题将解释如何使用 base64 模块的各种功能和数基。

1: 编码和解码 Base64

要在脚本中包含 base64 模块，必须先导入该模块：

import base64

base64 编码和解码函数都需要一个 bytes-like object。要将字符串转换成字节，我们必须使用 Python 内置的编码函数对其进行编码。最常用的是 UTF-8 编码，但是这些标准编码的完整列表（包括使用不同字符的语言）可以在 Python 官方文档 链接这里 中找到。下面是将字符串编码为字节的示例：

s = "Hello World!"
b = s.encode("UTF-8")

最后一行的输出结果是

b'Hello World!'

b 前缀用于表示值是字节对象。

要对这些字节进行 Base64 编码，我们需要使用 base64.b64encode() 函数：

import base64
s = "Hello World!"
b = s.encode("UTF-8")
e = base64.b64encode(b)
print(e)

该代码的输出结果如下

b'SGVsbG8gV29ybGQh'

仍在字节对象中。要从这些字节中获取字符串，我们可以使用 Python 的 decode() 方法，并使用 UTF-8 编码：

import base64
s = "Hello World!"
b = s.encode("UTF-8")
e = base64.b64encode(b)
s1 = e.decode("UTF-8")
print(s1)

输出结果将是

SGVsbG8gV29ybGQh

如果我们想对字符串进行编码然后解码，可以使用 base64.b64decode() 方法：

import base64
# Creating a string
s = "Hello World!"
# Encoding the string into bytes
b = s.encode("UTF-8")
# Base64 Encode the bytes
e = base64.b64encode(b)
# Decoding the Base64 bytes to string
s1 = e.decode("UTF-8")
# Printing Base64 encoded string
print("Base64 Encoded:", s1)
# Encoding the Base64 encoded string into bytes
b1 = s1.encode("UTF-8")
# Decoding the Base64 bytes
d = base64.b64decode(b1)
# Decoding the bytes to string
s2 = d.decode("UTF-8")
print(s2)

如您所料，输出将是原始字符串：

Base64 Encoded: SGVsbG8gV29ybGQh
Hello World!

2: 编码和解码 Base32

base64 模块还包括 Base32 的编码和解码函数。这些函数与 Base64 函数非常相似：

import base64

# Creating a string
s = "Hello World!"
# Encoding the string into bytes
b = s.encode("UTF-8")
# Base32 Encode the bytes
e = base64.b32encode(b)
# Decoding the Base32 bytes to string
s1 = e.decode("UTF-8")
# Printing Base32 encoded string
print("Base32 Encoded:", s1)
# Encoding the Base32 encoded string into bytes
b1 = s1.encode("UTF-8")
# Decoding the Base32 bytes
d = base64.b32decode(b1)
# Decoding the bytes to string
s2 = d.decode("UTF-8")
print(s2)

这将产生以下输出结果：

Base32 Encoded: JBSWY3DPEBLW64TMMQQQ====
Hello World!

3: 编码和解码 Base16

base64 “模块还包括 ”Base16 "的编码和解码函数。Base 16 "通常被称为十六进制。这些函数与 Base64 和 Base32 函数非常相似：

import base64
# Creating a string
s = "Hello World!"
# Encoding the string into bytes
b = s.encode("UTF-8")
# Base16 Encode the bytes
e = base64.b16encode(b)
# Decoding the Base16 bytes to string
s1 = e.decode("UTF-8")
# Printing Base16 encoded string
print("Base16 Encoded:", s1)
# Encoding the Base16 encoded string into bytes
b1 = s1.encode("UTF-8")
# Decoding the Base16 bytes
d = base64.b16decode(b1)
# Decoding the bytes to string
s2 = d.decode("UTF-8")
print(s2)

输出结果如下

Base16 Encoded: 48656C6C6F20576F726C6421
Hello World!

4: 编码和解码 ASCII85

Adobe 创建了自己的编码，称为 ASCII85，与 “Base85 ”相似，但也有不同之处。Adobe PDF 文件中经常使用这种编码。这些函数已在 Python 3.4 版本中发布。否则，函数 base64.a85encode() 和 base64.a85encode() 与前一个函数类似：

import base64
# Creating a string
s = "Hello World!"
# Encoding the string into bytes
b = s.encode("UTF-8")
# ASCII85 Encode the bytes
e = base64.a85encode(b)
# Decoding the ASCII85 bytes to string
s1 = e.decode("UTF-8")
# Printing ASCII85 encoded string
print("ASCII85 Encoded:", s1)
# Encoding the ASCII85 encoded string into bytes
b1 = s1.encode("UTF-8")
# Decoding the ASCII85 bytes
d = base64.a85decode(b1)
# Decoding the bytes to string
s2 = d.decode("UTF-8")
print(s2)

输出结果如下：

ASCII85 Encoded: 87cURD]i,"Ebo80
Hello World!

5: 编码和解码 Base85

Just like the Base64, Base32, and Base16 functions, the Base85 encoding and decoding functions are base64.b85encode() and base64.b85decode():

import base64

# Creating a string
s = "Hello World!"
# Encoding the string into bytes
b = s.encode("UTF-8")
# Base85 Encode the bytes
e = base64.b85encode(b)
# Decoding the Base85 bytes to string
s1 = e.decode("UTF-8")
# Printing Base85 encoded string
print("Base85 Encoded:", s1)
# Encoding the Base85 encoded string into bytes
b1 = s1.encode("UTF-8")
# Decoding the Base85 bytes
d = base64.b85decode(b1)
# Decoding the bytes to string
s2 = d.decode("UTF-8")
print(s2)

其输出结果如下：

Base85 Encoded: NM&qnZy;B1a%^NF
Hello World!