Tools for working with files
Useful for a temporary cd for use in a with statement:
- with cd(‘/Library/’):
will switch temporarily, and then switch back when leaving.
When we need to unpickle a function that might have relative paths (like some music21 stream options), Windows chokes if the PosixPath is not defined, but usually can still unpickle easily.
- music21.common.fileTools.readFileEncodingSafe(filePath, firstGuess='utf-8') str ¶
Slow, but will read a file of unknown encoding as safely as possible using the chardet package.
Let’s try to load this file as ascii – it has a copyright symbol at the top, so it won’t load in Python3:
>>> import os >>> c = str(common.getSourceFilePath() / 'common' / '__init__.py') >>> f = open(c) >>> data = f.read() Traceback (most recent call last): UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position ...: ordinal not in range(128)
That won’t do! now I know that it is in utf-8, but maybe you don’t. Or it could be an old humdrum or Noteworthy file with unknown encoding. This will load it safely.
>>> data = common.readFileEncodingSafe(c) >>> data[0:30] '# -*- coding: utf-8 -*-\n# ----'
Well, that’s nothing, since the first guess here is utf-8, and it’s right. So let’s give a worse first guess:
>>> data = common.readFileEncodingSafe(c, firstGuess='SHIFT_JIS') # old Japanese standard >>> data[0:30] '# -*- coding: utf-8 -*-\n# ----'
Note that this is slow enough if it gets it wrong that the firstGuess should be set to something reasonable like ‘ascii’ or ‘utf-8’.
- music21.common.fileTools.readPickleGzip(filePath: str | Path) Any ¶
Read a gzip-compressed pickle file, uncompress it, unpickle it, and return the contents.
After unpickling, leave pathlib alone.
Run a subprocess command, capturing stderr and only show the error if an exception is raised.