Contents

• StringIO和BytesIO用法

  • StringIO

    • 代码示例 1

    • 像读文件一样的使用StringIO

  • BytesIO

    • 像读文件一样的使用BytesIO

9.10. StringIO和BytesIO用法

9.10.1. StringIO

StringIO提供了一种像操作文本磁盘文件一样对内存缓存区数据操作的方法，

#!/usr/bin/env python
# -*- coding:utf8 -*-
# @auther:   18793
# @Date：    2020/6/22 11:05
# @filename: sample01.py
# @Email:    1879324764@qq.com
# @Software: PyCharm
from io import StringIO

f = StringIO()
for x in ["aa", 123, "file1", "ddd"]:
    if type(x) == str:
        f.write(x)
f.seek(0)
xx = f.read()
print("xx = %s " % xx)
yy = f.getvalue()
print("yy = %s " % yy)

代码示例 1

#!/usr/bin/env python
# -*- coding:utf8 -*-
# auther; 18793
# Date：2019/9/10 9:22
# filename: string_io.py
from io import StringIO

io_val = StringIO()
io_val.write("hello")

# getvalue()方法用于获得写入后的str
print("say:{}".format(io_val.getvalue()))

"""
say:hello
"""

• getvalue()方法用于获得写入后的str

像读文件一样的使用StringIO

代码示例

#!/usr/bin/env python
# -*- coding:utf8 -*-
# auther; 18793
# Date：2019/9/10 9:24
# filename: str_io_read.py

from io import StringIO

io_val = StringIO("Hello\nWorld\nWellcome!")
while True:
    line = io_val.readline()
    if line == '':
        break
    print("line value:{}".format(line.strip()))

"""
line value:Hello
line value:World
line value:Wellcome!
"""

9.10.2. BytesIO

• BytesIO实现了在内存中读写bytes，我们创建一个BytesIO，然后写入一些bytes

• 读写BytesIOBytesIO提供了一种像操作二进制磁盘文件一样对内存缓存区数据操作的方法

代码示例

#!/usr/bin/env python
# -*- coding:utf8 -*-
# @auther:   18793
# @Date：    2020/6/22 11:11
# @filename: sample01.py
# @Email:    1879324764@qq.com
# @Software: PyCharm
import pickle
from io import BytesIO

f = BytesIO()
for x in ["aa", 123, "file", "dddd", True]:
    pickle.dump(x, f)

f.seek(0)

while True:
    try:
        xx = pickle.load(f)
        print("xx = ", xx)
    except EOFError:
        break

In [22]: from io import BytesIO
In [23]: f = BytesIO(0
   ....:
KeyboardInterrupt

In [23]: f = BytesIO()

In [24]: f.write('中文'.encode('utf-8'))
Out[24]: 6

In [25]: print(f.getvalue())
b'\xe4\xb8\xad\xe6\x96\x87'

像读文件一样的使用BytesIO

代码示例

In [26]: from io import BytesIO

In [27]: f = BytesIO(b'\xe4\xb8\xad\xe6\x96\x87')

In [28]: f.read()
Out[28]: b'\xe4\xb8\xad\xe6\x96\x87'