8.3.6 读取Unicode数据
前面的例子直接使用BZ2File,并在必要时用一个io.TextIOWrapper来管理Unicode文本串的编码和解码。通过使用bz2.open()可以避免这些额外的步骤,这会建立一个io.TextIOWrapper以自动处理编码或解码。
import bz2
import os
data = 'Character with on ãccent.'
with bz2.open('example.bz2','wt',encoding='utf-8') as output:
output.write(data)
with bz2.open('example.bz2','rt',encoding='utf-8') as input:
print('Full file: {}'.format(input.read()))
# Move to the beginning of the accented character:
with bz2.open('example.bz2','rt',encoding='utf-8') as input:
input.seek(18)
print('One character: {}'.format(input.read(1)))
# Move to the middle of the accented character.
with bz2.open('example.bz2','rt',encoding='utf-8') as input:
input.seek(19)
try:
print(input.read(1))
except UnicodeDecodeError:
print('ERROR: failed to decode')
open()返回的文件句柄支持seek(),不过使用时要小心,因为文件指针按字节移动,而不是按字符移动,最后可能会落在一个编码字符的中间。
运行结果: