base64io¶
This project is designed to develop a class, base64io.Base64IO, that implements
a streaming interface for Base64 encoding.
Python has supported native Base64 encoding since version 2.4. However, there is no streaming interface for Base64 encoding, and none is available from the community.
The legacy base64.encode and base64.decode interface lets you shuffle data between
two streams, but it assumes that you have two complete streams. We wanted a
standard stream that applies Base64 encoding and decoding.
base64io.Base64IO provides an io streaming interface with context manager
support that transparently Base64-encodes data read from it. You can use it to transform
large files without caching the entire context in memory, or to transform an existing
stream.
For the latest full documentation, see Read the Docs.
Find us on GitHub.
Getting Started¶
base64io.Base64IO has no dependencies other than the standard library and should
work with any version of Python greater than 2.6. We test it on CPython 2.6, 2.7, 3.3,
3.4, 3.5, 3.6, and 3.7.
Installation¶
$ pip install base64io
Use¶
base64io.Base64IO wraps the input stream and transparently encodes or decodes
data written to or read from the input stream.
write()encodes data before writing it to the wrapped streamread()decodes data after reading it from the wrapped stream
Because the position of the base64io.Base64IO stream and the wrapped stream will
almost always be different, base64io.Base64IO does not support:
seek()tell()
Also, base64io.Base64IO does not support:
fileno()truncate()
Encode data¶
Warning
If you are not using base64io.Base64IO as a context manager, when you write to
a base64io.Base64IO stream, you must close the stream after your final
write. The Base64 transformation might hold up to two bytes of unencoded data in an
internal buffer before writing it to the wrapped stream. Calling close() flushes
this buffer and writes the padded result to the wrapped stream. The
base64io.Base64IO context manager does this for you.
from base64io import Base64IO
with open("source_file", "rb") as source, open("encoded_file", "wb") as target:
with Base64IO(target) as encoded_target:
for line in source:
encoded_target.write(line)
Decode data¶
Note
When it reads data from the wrapping stream, it might read up to three additional bytes from the underlying stream.
from base64io import Base64IO
with open("encoded_file", "rb") as encoded_source, open("target_file", "wb") as target:
with Base64IO(encoded_source) as source:
for line in source:
target.write(line)
License¶
This library is licensed under the Apache 2.0 License.