python3 字符串str和bytes的相互转换
1.相关基础(python3中有两种字符串类型:str和bytes)
str以unicode编码格式保存在内存
所以使用时,不用管前面要不要加u
(python2中需要考虑,不加u的话,在一些场合会报错)
#!/usr/bin/python3
str0="i am fine thank you"
print(type(str0))
print(str0)
str0=u"i am fine thank you"
print(type(str0))
print(str0)
# <class 'str'>
# i am fine thank you
# <class 'str'>
# i am fine thank you
定义byte类型时,在字符串前加b
#!/usr/bin/python3
str0=b"i am fine thank you"
print(type(str0))
print(str0)
# <class 'bytes'>
# b'i am fine thank you'
2.str和bytes相互转换
在文件传输过程中,通常使用bytes格式的数据流,而代码中通常用str类型,因此str和bytes的相互转换就尤为重要。
2.1 bytes->str
#!/usr/bin/python3
bytes_data = b'this is a message'
print(type(bytes_data))
print(bytes_data)
# 方法一:
str_data = str(bytes_data, encoding='utf-8')
print(type(str_data))
print(str_data)
# 方法二:
str_data = bytes_data.decode('utf-8')
print(type(str_data))
print(str_data)
# <class 'bytes'>
# b'this is a message'
# <class 'str'>
# this is a message
# <class 'str'>
# this is a message
2.2 str->bytes
#!/usr/bin/python3
str_data = 'this is a message'
print(type(str_data))
print(str_data)
# 方法一:
bytes_data = bytes(str_data, encoding='utf-8')
print(type(bytes_data))
print(bytes_data)
# 方法二:
bytes_data = str_data.encode('utf-8')
print(type(bytes_data))
print(bytes_data)
# <class 'str'>
# this is a message
# <class 'bytes'>
# b'this is a message'
# <class 'bytes'>
# b'this is a message'
来源:Newjet666