bytes 与 str 转换

Python3 最重要的特性之一就是对 字符串 和 二进制字节 做了明确且严格的区分，之所以说严格，是指二者在任何情况下不能混用；

文本总是 Unicode，由字符串 str 表示；

二进制数据由 bytes 表示；

file1 = open('data.txt', 'r')
out1 = file1.read()
print(type(out1))       # <class 'str'>

### 以二进制方式读取
file2 = open('data.txt', 'rb')
out2 = file2.read()
print(type(out2))       # <class 'bytes'>

# print(out1 + out2)      # TypeError: must be str, not bytes

二者相互转换

b = b'hello'
s = 'world'

print(type(b))      # <class 'bytes'>
print(type(s))      # <class 'str'>


### btyes to str
# def __init__(self, value='', encoding=None, errors='strict')
bs1 = str(b, encoding='utf-8')

# def decode(self, *args, **kwargs)
bs2 = bytes.decode(b, encoding='utf-8')
print(type(bs1), type(bs2))         # <class 'str'> <class 'str'>


### str to bytes
# def __init__(self, value=b'', encoding=None, errors='strict')
sb1 = bytes(s, encoding='utf-8')

# def encode(self, encoding='utf-8', errors='strict')
sb2 = str.encode(s, encoding='utf-8')
print(type(sb1), type(sb2))         # <class 'bytes'> <class 'bytes'>

用图总结转换方法

参考资料：

https://www.ituring.com.cn/article/1116