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# parsePythonValue.py
#
# Copyright, 2006, by Paul McGuire
#
import pyparsing as pp
from pyparsing import ParseResults, autoname_elements
convert_bool = lambda t: t[0] == "True"
convert_int = lambda toks: int(toks[0])
convert_real = lambda toks: float(toks[0])
convert_tuple = lambda toks: tuple(toks.as_list())
convert_set = lambda toks: set(toks.as_list())
convert_dict = lambda toks: dict(toks.as_list())
convert_list = lambda toks: [toks.as_list()]
# define punctuation as suppressed literals
lparen, rparen, lbrack, rbrack, lbrace, rbrace, colon, comma = pp.Suppress.using_each("()[]{}:,")
integer = pp.Regex(r"[+-]?\d+").set_name("integer").add_parse_action(convert_int)
real = pp.Regex(r"[+-]?\d+\.\d*([Ee][+-]?\d+)?").set_name("real").add_parse_action(convert_real)
# containers must be defined using a Forward, since they get parsed recursively
tuple_str = pp.Forward().set_name("tuple_expr")
list_str = pp.Forward().set_name("list_expr")
set_str = pp.Forward().set_name("set_expr")
dict_str = pp.Forward().set_name("dict_expr")
quoted_str = pp.quoted_string().add_parse_action(lambda t: t[0][1:-1])
bool_literal = pp.one_of("True False", as_keyword=True).add_parse_action(convert_bool)
none_literal = pp.Keyword("None").add_parse_action(pp.replace_with(None))
list_item = (
real
| integer
| quoted_str
| bool_literal
| none_literal
| pp.Group(list_str)
| tuple_str
| set_str
| dict_str
).set_name("list_item")
# tuple must have a comma-separated list of 2 or more items, with optional
# trailing comma, or a single item with required trailing comma
tuple_str <<= (
lparen + pp.Opt(
pp.DelimitedList(list_item, min=2, allow_trailing_delim=True)
| list_item + comma
)
+ rparen
)
tuple_str.add_parse_action(convert_tuple)
set_str <<= (
lbrace + pp.DelimitedList(list_item, allow_trailing_delim=True) + rbrace
)
set_str.add_parse_action(convert_set)
list_str <<= (
lbrack + pp.Opt(pp.DelimitedList(list_item, allow_trailing_delim=True)) + rbrack
)
list_str.add_parse_action(convert_list, lambda t: t[0])
dict_entry = pp.Group(list_item + colon + list_item).set_name("dict_entry")
dict_str <<= (
lbrace + pp.Opt(pp.DelimitedList(dict_entry, allow_trailing_delim=True)) + rbrace
)
dict_str.add_parse_action(convert_dict)
python_value = list_item
autoname_elements()
def main():
from ast import literal_eval
import contextlib
with contextlib.suppress(Exception):
list_item.create_diagram("parse_python_value.html")
non_list_tests = """\
# dict of str to int or dict
{ 'A':1, 'B':2, 'C': {'a': 1.2, 'b': 3.4} }
# dict of str or tuple keys
{'A':1, 'B':2, (1, 2): {'a', 1.2, 'b', 3.4}}
# empty dict
{}
# set of mixed types
{1, 2, 11, "blah"}
# empty set
{()}
# a tuple of mixed types
('A', 100, -2.71828, {'b':99})
# a tuple with just one value
('A',)
# empty tuple
()
# float
3.14159
# int
42
# float in scientific notation
6.02E23
6.02e+023
1.0e-7
# quoted string
'a quoted string'
"""
list_tests = """\
# list of mixed types
['a', 100, ('A', [101,102]), 3.14, [ +2.718, 'xyzzy', -1.414] ]
# list of dicts
[{0: [2], 1: []}, {0: [], 1: [], 2: []}, {0: [1, 2]}]
# empty list
[]
"""
def validate_parsed_value(test_str: str, result: ParseResults) -> bool:
python_value = literal_eval(test_str)
return python_value == result[0]
def validate_parsed_list(test_str: str, result: ParseResults) -> bool:
python_value = literal_eval(test_str)
return python_value == result.as_list()[0]
success1, report_1 = list_item.run_tests(non_list_tests)
success1 = success1 and all(validate_parsed_value(*rpt) for rpt in report_1)
success2, report_2 = list_item.run_tests(list_tests)
success2 = success2 and all(validate_parsed_list(*rpt) for rpt in report_2)
assert success1 and success2
if __name__ == "__main__":
main()
|
