Autoparse Tutorial

Autoparse allows for user-friendly regex usage to parse for information. Consider if you had the following string:

>>> mystring = ' ___A_a_ * & b ___c_ C 1d 2 __e_ D__'

We can use autoparse to work with the string

>>> import autoparse
>>> autoparse.find.split_words(mystring)
('___A_a_', '*', '&', 'b', '___c_', 'C', '1d', '2', '__e_', 'D__')

Or we can capture specific patterns

>>> pattern = autoparse.pattern.capturing(autoparse.pattern.UPPERCASE_LETTER)
>>> autoparse.find.all_captures(pattern, mystring)
('A', 'C', 'D')
>>> pattern = autoparse.pattern.capturing(autoparse.pattern.DIGIT)
>>> autoparse.find.first_capture(pattern, mystring)
'1'

We can also use autoparse to make sure a string is formatted as expected

>>> message = 'Greetings, user'
>>> autoparse.find.starts_with('Greet', message)
True
>>> autoparse.find.ends_with('goodbye', message)
False
>>> mynumber = '  400 '
>>> autoparse.find.is_number(mynumber)
True

Now that you’ve got the basics, lets see how autoparse can help us parse real data we’ll encounter in AutoMech. We are defining a search pattern that will parse the cartesian coordinates out of a file.

>>> atom_symbols = (
...     autoparse.pattern.LETTER +
...     autoparse.pattern.maybe(autoparse.pattern.LETTER)
... )
>>> number = autoparse.pattern.FLOAT
>>> xyz_lines = autoparse.pattern.LINESPACES.join([
...     autoparse.pattern.capturing(atom_symbols),
...     autoparse.pattern.capturing(number),
...     autoparse.pattern.capturing(number),
...     autoparse.pattern.capturing(number),
... ])

Now we can put in an example xyz string

>>> xyz_string = """
... dummy line 1
... another dummy line
...
... that dummy line was blank
... 6
... charge: 0, mult: 1
... F    1.584823  -0.748487  -0.427122
... C    0.619220   0.190166  -0.271639
... C   -0.635731  -0.183914  -0.180364
... Cl  -1.602333   0.736678  -0.026051
... H    0.916321   1.229946  -0.227127
... H   -0.882300  -1.224388  -0.229636
... let's end on a dummy line
... """

>>> autoparse.cast(autoparse.find.all_captures(xyz_lines, xyz_string))
(('F', 1.584823, -0.748487, -0.427122), ('C', 0.61922, 0.190166, -0.271639), ('C', -0.635731, -0.183914, -0.180364), ('Cl', -1.602333, 0.736678, -0.026051), ('H', 0.916321, 1.229946, -0.227127), ('H', -0.8823, -1.224388, -0.229636))

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