strscan.Scanner is a near-direct port of Ruby's StringScanner.
The aim is to provide for lexical scanning operations on strings:
>>> from strscan import Scanner >>> s = Scanner("This is an example string") >>> s.eos() False >>> s.scan(r'\w+') 'This' >>> s.scan(r'\w+') >>> s.scan(r'\s+') ' ' >>> s.scan(r'\s+') >>> s.scan(r'\w+') 'is' >>> s.eos() False >>> s.scan(r'\s+') ' ' >>> s.scan(r'\w+') 'an' >>> s.scan(r'\s+') ' ' >>> s.scan(r'\w+') 'example' >>> s.scan(r'\s+') ' ' >>> s.scan(r'\w+') 'string' >>> s.eos() True >>> s.scan(r'\s+') >>> s.scan(r'\w+')
Its mechanism of operation is similar to StringIO, only instead of reading by passing a number of bytes, you read by passing a regex. A scan pointer tracks the current position through the string, and all scanning or searching happens on the rest of the string after this pointer. scan is the simple case of reading some text and advancing the scan pointer, but there are several other related methods which fulfil different requirements.
All the methods on Scanner which take regexes will accept either regex strings or compiled pattern objects (as would be returned from re.compile()).
There's also a useful function provided, text_coords(), which resolves simple string indices into textual co-ordinates (line number and column):
>>> s = "abcdef\nghijkl\nmnopqr\nstuvwx\nyz" >>> text_coords(s, 0) (0, 0, 'abcdef') >>> text_coords(s, 4) (0, 4, 'abcdef') >>> text_coords(s, 6) (0, 6, 'abcdef') >>> text_coords(s, 7) (1, 0, 'ghijkl') >>> text_coords(s, 11) (1, 4, 'ghijkl') >>> text_coords(s, 15) (2, 1, 'mnopqr')
You can get the module from PyPI:
pip install strscan
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