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# results.py
from collections.abc import MutableMapping, Mapping, MutableSequence, Iterator
import pprint
from weakref import ref as wkref
from typing import Tuple, Any
str_type: Tuple[type, ...] = (str, bytes)
_generator_type = type((_ for _ in ()))
class _ParseResultsWithOffset:
__slots__ = ["tup"]
def __init__(self, p1, p2):
self.tup = (p1, p2)
def __getitem__(self, i):
return self.tup[i]
def __getstate__(self):
return self.tup
def __setstate__(self, *args):
self.tup = args[0]
class ParseResults:
"""Structured parse results, to provide multiple means of access to
the parsed data:
- as a list (``len(results)``)
- by list index (``results[0], results[1]``, etc.)
- by attribute (``results.<results_name>`` - see :class:`ParserElement.set_results_name`)
Example::
integer = Word(nums)
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
# date_str = (integer("year") + '/'
# + integer("month") + '/'
# + integer("day"))
# parse_string returns a ParseResults object
result = date_str.parse_string("1999/12/31")
def test(s, fn=repr):
print("{} -> {}".format(s, fn(eval(s))))
test("list(result)")
test("result[0]")
test("result['month']")
test("result.day")
test("'month' in result")
test("'minutes' in result")
test("result.dump()", str)
prints::
list(result) -> ['1999', '/', '12', '/', '31']
result[0] -> '1999'
result['month'] -> '12'
result.day -> '31'
'month' in result -> True
'minutes' in result -> False
result.dump() -> ['1999', '/', '12', '/', '31']
- day: '31'
- month: '12'
- year: '1999'
"""
_null_values: Tuple[Any, ...] = (None, [], "", ())
__slots__ = [
"_name",
"_parent",
"_all_names",
"_modal",
"_toklist",
"_tokdict",
"__weakref__",
]
class List(list):
"""
Simple wrapper class to distinguish parsed list results that should be preserved
as actual Python lists, instead of being converted to :class:`ParseResults`:
LBRACK, RBRACK = map(pp.Suppress, "[]")
element = pp.Forward()
item = ppc.integer
element_list = LBRACK + pp.delimited_list(element) + RBRACK
# add parse actions to convert from ParseResults to actual Python collection types
def as_python_list(t):
return pp.ParseResults.List(t.as_list())
element_list.add_parse_action(as_python_list)
element <<= item | element_list
element.run_tests('''
100
[2,3,4]
[[2, 1],3,4]
[(2, 1),3,4]
(2,3,4)
''', post_parse=lambda s, r: (r[0], type(r[0])))
prints:
100
(100, <class 'int'>)
[2,3,4]
([2, 3, 4], <class 'list'>)
[[2, 1],3,4]
([[2, 1], 3, 4], <class 'list'>)
(Used internally by :class:`Group` when `aslist=True`.)
"""
def __new__(cls, contained=None):
if contained is None:
contained = []
if not isinstance(contained, list):
raise TypeError(
"{} may only be constructed with a list,"
" not {}".format(cls.__name__, type(contained).__name__)
)
return list.__new__(cls)
def __new__(cls, toklist=None, name=None, **kwargs):
if isinstance(toklist, ParseResults):
return toklist
self = object.__new__(cls)
self._name = None
self._parent = None
self._all_names = set()
if toklist is None:
self._toklist = []
elif isinstance(toklist, (list, _generator_type)):
self._toklist = (
[toklist[:]]
if isinstance(toklist, ParseResults.List)
else list(toklist)
)
else:
self._toklist = [toklist]
self._tokdict = dict()
return self
# Performance tuning: we construct a *lot* of these, so keep this
# constructor as small and fast as possible
def __init__(
self, toklist=None, name=None, asList=True, modal=True, isinstance=isinstance
):
self._modal = modal
if name is not None and name != "":
if isinstance(name, int):
name = str(name)
if not modal:
self._all_names = {name}
self._name = name
if toklist not in self._null_values:
if isinstance(toklist, (str_type, type)):
toklist = [toklist]
if asList:
if isinstance(toklist, ParseResults):
self[name] = _ParseResultsWithOffset(
ParseResults(toklist._toklist), 0
)
else:
self[name] = _ParseResultsWithOffset(
ParseResults(toklist[0]), 0
)
self[name]._name = name
else:
try:
self[name] = toklist[0]
except (KeyError, TypeError, IndexError):
if toklist is not self:
self[name] = toklist
else:
self._name = name
def __getitem__(self, i):
if isinstance(i, (int, slice)):
return self._toklist[i]
else:
if i not in self._all_names:
return self._tokdict[i][-1][0]
else:
return ParseResults([v[0] for v in self._tokdict[i]])
def __setitem__(self, k, v, isinstance=isinstance):
if isinstance(v, _ParseResultsWithOffset):
self._tokdict[k] = self._tokdict.get(k, list()) + [v]
sub = v[0]
elif isinstance(k, (int, slice)):
self._toklist[k] = v
sub = v
else:
self._tokdict[k] = self._tokdict.get(k, list()) + [
_ParseResultsWithOffset(v, 0)
]
sub = v
if isinstance(sub, ParseResults):
sub._parent = wkref(self)
def __delitem__(self, i):
if isinstance(i, (int, slice)):
mylen = len(self._toklist)
del self._toklist[i]
# convert int to slice
if isinstance(i, int):
if i < 0:
i += mylen
i = slice(i, i + 1)
# get removed indices
removed = list(range(*i.indices(mylen)))
removed.reverse()
# fixup indices in token dictionary
for name, occurrences in self._tokdict.items():
for j in removed:
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(
value, position - (position > j)
)
else:
del self._tokdict[i]
def __contains__(self, k) -> bool:
return k in self._tokdict
def __len__(self) -> int:
return len(self._toklist)
def __bool__(self) -> bool:
return not not (self._toklist or self._tokdict)
def __iter__(self) -> Iterator:
return iter(self._toklist)
def __reversed__(self) -> Iterator:
return iter(self._toklist[::-1])
def keys(self):
return iter(self._tokdict)
def values(self):
return (self[k] for k in self.keys())
def items(self):
return ((k, self[k]) for k in self.keys())
def haskeys(self) -> bool:
"""
Since ``keys()`` returns an iterator, this method is helpful in bypassing
code that looks for the existence of any defined results names."""
return bool(self._tokdict)
def pop(self, *args, **kwargs):
"""
Removes and returns item at specified index (default= ``last``).
Supports both ``list`` and ``dict`` semantics for ``pop()``. If
passed no argument or an integer argument, it will use ``list``
semantics and pop tokens from the list of parsed tokens. If passed
a non-integer argument (most likely a string), it will use ``dict``
semantics and pop the corresponding value from any defined results
names. A second default return value argument is supported, just as in
``dict.pop()``.
Example::
numlist = Word(nums)[...]
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321']
def remove_first(tokens):
tokens.pop(0)
numlist.add_parse_action(remove_first)
print(numlist.parse_string("0 123 321")) # -> ['123', '321']
label = Word(alphas)
patt = label("LABEL") + Word(nums)[1, ...]
print(patt.parse_string("AAB 123 321").dump())
# Use pop() in a parse action to remove named result (note that corresponding value is not
# removed from list form of results)
def remove_LABEL(tokens):
tokens.pop("LABEL")
return tokens
patt.add_parse_action(remove_LABEL)
print(patt.parse_string("AAB 123 321").dump())
prints::
['AAB', '123', '321']
- LABEL: 'AAB'
['AAB', '123', '321']
"""
if not args:
args = [-1]
for k, v in kwargs.items():
if k == "default":
args = (args[0], v)
else:
raise TypeError(
"pop() got an unexpected keyword argument {!r}".format(k)
)
if isinstance(args[0], int) or len(args) == 1 or args[0] in self:
index = args[0]
ret = self[index]
del self[index]
return ret
else:
defaultvalue = args[1]
return defaultvalue
def get(self, key, default_value=None):
"""
Returns named result matching the given key, or if there is no
such name, then returns the given ``default_value`` or ``None`` if no
``default_value`` is specified.
Similar to ``dict.get()``.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parse_string("1999/12/31")
print(result.get("year")) # -> '1999'
print(result.get("hour", "not specified")) # -> 'not specified'
print(result.get("hour")) # -> None
"""
if key in self:
return self[key]
else:
return default_value
def insert(self, index, ins_string):
"""
Inserts new element at location index in the list of parsed tokens.
Similar to ``list.insert()``.
Example::
numlist = Word(nums)[...]
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321']
# use a parse action to insert the parse location in the front of the parsed results
def insert_locn(locn, tokens):
tokens.insert(0, locn)
numlist.add_parse_action(insert_locn)
print(numlist.parse_string("0 123 321")) # -> [0, '0', '123', '321']
"""
self._toklist.insert(index, ins_string)
# fixup indices in token dictionary
for name, occurrences in self._tokdict.items():
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(
value, position + (position > index)
)
def append(self, item):
"""
Add single element to end of ``ParseResults`` list of elements.
Example::
numlist = Word(nums)[...]
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321']
# use a parse action to compute the sum of the parsed integers, and add it to the end
def append_sum(tokens):
tokens.append(sum(map(int, tokens)))
numlist.add_parse_action(append_sum)
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321', 444]
"""
self._toklist.append(item)
def extend(self, itemseq):
"""
Add sequence of elements to end of ``ParseResults`` list of elements.
Example::
patt = Word(alphas)[1, ...]
# use a parse action to append the reverse of the matched strings, to make a palindrome
def make_palindrome(tokens):
tokens.extend(reversed([t[::-1] for t in tokens]))
return ''.join(tokens)
patt.add_parse_action(make_palindrome)
print(patt.parse_string("lskdj sdlkjf lksd")) # -> 'lskdjsdlkjflksddsklfjkldsjdksl'
"""
if isinstance(itemseq, ParseResults):
self.__iadd__(itemseq)
else:
self._toklist.extend(itemseq)
def clear(self):
"""
Clear all elements and results names.
"""
del self._toklist[:]
self._tokdict.clear()
def __getattr__(self, name):
try:
return self[name]
except KeyError:
if name.startswith("__"):
raise AttributeError(name)
return ""
def __add__(self, other) -> "ParseResults":
ret = self.copy()
ret += other
return ret
def __iadd__(self, other) -> "ParseResults":
if other._tokdict:
offset = len(self._toklist)
addoffset = lambda a: offset if a < 0 else a + offset
otheritems = other._tokdict.items()
otherdictitems = [
(k, _ParseResultsWithOffset(v[0], addoffset(v[1])))
for k, vlist in otheritems
for v in vlist
]
for k, v in otherdictitems:
self[k] = v
if isinstance(v[0], ParseResults):
v[0]._parent = wkref(self)
self._toklist += other._toklist
self._all_names |= other._all_names
return self
def __radd__(self, other) -> "ParseResults":
if isinstance(other, int) and other == 0:
# useful for merging many ParseResults using sum() builtin
return self.copy()
else:
# this may raise a TypeError - so be it
return other + self
def __repr__(self) -> str:
return "{}({!r}, {})".format(type(self).__name__, self._toklist, self.as_dict())
def __str__(self) -> str:
return (
"["
+ ", ".join(
[
str(i) if isinstance(i, ParseResults) else repr(i)
for i in self._toklist
]
)
+ "]"
)
def _asStringList(self, sep=""):
out = []
for item in self._toklist:
if out and sep:
out.append(sep)
if isinstance(item, ParseResults):
out += item._asStringList()
else:
out.append(str(item))
return out
def as_list(self) -> list:
"""
Returns the parse results as a nested list of matching tokens, all converted to strings.
Example::
patt = Word(alphas)[1, ...]
result = patt.parse_string("sldkj lsdkj sldkj")
# even though the result prints in string-like form, it is actually a pyparsing ParseResults
print(type(result), result) # -> <class 'pyparsing.ParseResults'> ['sldkj', 'lsdkj', 'sldkj']
# Use as_list() to create an actual list
result_list = result.as_list()
print(type(result_list), result_list) # -> <class 'list'> ['sldkj', 'lsdkj', 'sldkj']
"""
return [
res.as_list() if isinstance(res, ParseResults) else res
for res in self._toklist
]
def as_dict(self) -> dict:
"""
Returns the named parse results as a nested dictionary.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parse_string('12/31/1999')
print(type(result), repr(result)) # -> <class 'pyparsing.ParseResults'> (['12', '/', '31', '/', '1999'], {'day': [('1999', 4)], 'year': [('12', 0)], 'month': [('31', 2)]})
result_dict = result.as_dict()
print(type(result_dict), repr(result_dict)) # -> <class 'dict'> {'day': '1999', 'year': '12', 'month': '31'}
# even though a ParseResults supports dict-like access, sometime you just need to have a dict
import json
print(json.dumps(result)) # -> Exception: TypeError: ... is not JSON serializable
print(json.dumps(result.as_dict())) # -> {"month": "31", "day": "1999", "year": "12"}
"""
def to_item(obj):
if isinstance(obj, ParseResults):
return obj.as_dict() if obj.haskeys() else [to_item(v) for v in obj]
else:
return obj
return dict((k, to_item(v)) for k, v in self.items())
def copy(self) -> "ParseResults":
"""
Returns a new copy of a :class:`ParseResults` object.
"""
ret = ParseResults(self._toklist)
ret._tokdict = self._tokdict.copy()
ret._parent = self._parent
ret._all_names |= self._all_names
ret._name = self._name
return ret
def get_name(self):
r"""
Returns the results name for this token expression. Useful when several
different expressions might match at a particular location.
Example::
integer = Word(nums)
ssn_expr = Regex(r"\d\d\d-\d\d-\d\d\d\d")
house_number_expr = Suppress('#') + Word(nums, alphanums)
user_data = (Group(house_number_expr)("house_number")
| Group(ssn_expr)("ssn")
| Group(integer)("age"))
user_info = user_data[1, ...]
result = user_info.parse_string("22 111-22-3333 #221B")
for item in result:
print(item.get_name(), ':', item[0])
prints::
age : 22
ssn : 111-22-3333
house_number : 221B
"""
if self._name:
return self._name
elif self._parent:
par = self._parent()
def find_in_parent(sub):
return next(
(
k
for k, vlist in par._tokdict.items()
for v, loc in vlist
if sub is v
),
None,
)
return find_in_parent(self) if par else None
elif (
len(self) == 1
and len(self._tokdict) == 1
and next(iter(self._tokdict.values()))[0][1] in (0, -1)
):
return next(iter(self._tokdict.keys()))
else:
return None
def dump(self, indent="", full=True, include_list=True, _depth=0) -> str:
"""
Diagnostic method for listing out the contents of
a :class:`ParseResults`. Accepts an optional ``indent`` argument so
that this string can be embedded in a nested display of other data.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parse_string('1999/12/31')
print(result.dump())
prints::
['1999', '/', '12', '/', '31']
- day: '31'
- month: '12'
- year: '1999'
"""
out = []
NL = "\n"
out.append(indent + str(self.as_list()) if include_list else "")
if full:
if self.haskeys():
items = sorted((str(k), v) for k, v in self.items())
for k, v in items:
if out:
out.append(NL)
out.append("{}{}- {}: ".format(indent, (" " * _depth), k))
if isinstance(v, ParseResults):
if v:
out.append(
v.dump(
indent=indent,
full=full,
include_list=include_list,
_depth=_depth + 1,
)
)
else:
out.append(str(v))
else:
out.append(repr(v))
if any(isinstance(vv, ParseResults) for vv in self):
v = self
for i, vv in enumerate(v):
if isinstance(vv, ParseResults):
out.append(
"\n{}{}[{}]:\n{}{}{}".format(
indent,
(" " * (_depth)),
i,
indent,
(" " * (_depth + 1)),
vv.dump(
indent=indent,
full=full,
include_list=include_list,
_depth=_depth + 1,
),
)
)
else:
out.append(
"\n%s%s[%d]:\n%s%s%s"
% (
indent,
(" " * (_depth)),
i,
indent,
(" " * (_depth + 1)),
str(vv),
)
)
return "".join(out)
def pprint(self, *args, **kwargs):
"""
Pretty-printer for parsed results as a list, using the
`pprint <https://docs.python.org/3/library/pprint.html>`_ module.
Accepts additional positional or keyword args as defined for
`pprint.pprint <https://docs.python.org/3/library/pprint.html#pprint.pprint>`_ .
Example::
ident = Word(alphas, alphanums)
num = Word(nums)
func = Forward()
term = ident | num | Group('(' + func + ')')
func <<= ident + Group(Optional(delimited_list(term)))
result = func.parse_string("fna a,b,(fnb c,d,200),100")
result.pprint(width=40)
prints::
['fna',
['a',
'b',
['(', 'fnb', ['c', 'd', '200'], ')'],
'100']]
"""
pprint.pprint(self.as_list(), *args, **kwargs)
# add support for pickle protocol
def __getstate__(self):
return (
self._toklist,
(
self._tokdict.copy(),
self._parent is not None and self._parent() or None,
self._all_names,
self._name,
),
)
def __setstate__(self, state):
self._toklist, (self._tokdict, par, inAccumNames, self._name) = state
self._all_names = set(inAccumNames)
if par is not None:
self._parent = wkref(par)
else:
self._parent = None
def __getnewargs__(self):
return self._toklist, self._name
def __dir__(self):
return dir(type(self)) + list(self.keys())
@classmethod
def from_dict(cls, other, name=None) -> "ParseResults":
"""
Helper classmethod to construct a ``ParseResults`` from a ``dict``, preserving the
name-value relations as results names. If an optional ``name`` argument is
given, a nested ``ParseResults`` will be returned.
"""
def is_iterable(obj):
try:
iter(obj)
except Exception:
return False
else:
return not isinstance(obj, str_type)
ret = cls([])
for k, v in other.items():
if isinstance(v, Mapping):
ret += cls.from_dict(v, name=k)
else:
ret += cls([v], name=k, asList=is_iterable(v))
if name is not None:
ret = cls([ret], name=name)
return ret
asList = as_list
asDict = as_dict
getName = get_name
MutableMapping.register(ParseResults)
MutableSequence.register(ParseResults)
|