def _extract_charge(arg: str):
"""
Receive a `str` representing an element, isotope, or ion.
Return a `tuple` containing a `str` that should represent an
element or isotope, and either an `int` representing the
charge or `None` if no charge information is provided. Raise
an `~plasmapy.utils.InvalidParticleError` if charge information
is inputted incorrectly.
"""
invalid_charge_errmsg = (f"Invalid charge information in the particle string '{arg}'.")
if arg.count(' ') == 1: # Cases like 'H 1-' and 'Fe-56 1+'
isotope_info, charge_info = arg.split(' ')
sign_indicator_only_on_one_end = (
charge_info.endswith(('-', '+')) ^
charge_info.startswith(('-', '+')))
just_one_sign_indicator = (
(charge_info.count('-') == 1 and
charge_info.count('+') == 0) or
(charge_info.count('-') == 0 and
charge_info.count('+') == 1))
if not sign_indicator_only_on_one_end and just_one_sign_indicator:
raise InvalidParticleError(invalid_charge_errmsg) from None
charge_str = charge_info.strip('+-')
try:
if roman.is_roman_numeral(charge_info):
Z_from_arg = roman.from_roman(charge_info) - 1
elif '-' in charge_info:
Z_from_arg = - int(charge_str)
elif '+' in charge_info:
Z_from_arg = int(charge_str)
else:
raise InvalidParticleError(invalid_charge_errmsg) from None
except ValueError:
raise InvalidParticleError(invalid_charge_errmsg) from None
elif arg.endswith(('-', '+')): # Cases like 'H-' and 'Pb-209+++'
char = arg[-1]
match = re.match(f"[{char}]*", arg[::-1])
Z_from_arg = match.span()[1]
isotope_info = arg[0:len(arg) - match.span()[1]]
if char == '-':
Z_from_arg = -Z_from_arg
if isotope_info.endswith(('-', '+')):
raise InvalidParticleError(invalid_charge_errmsg) from None
else:
isotope_info = arg
Z_from_arg = None
return isotope_info, Z_from_arg
def __init__(self, ion_name, hdf5_dbase_root=None, **kwargs):
self._element, ion = ion_name.split()
if '+' in ion:
ion = f"{int(ion.strip('+')) + 1}"
if roman.is_roman_numeral(ion.upper()):
ion = roman.from_roman(ion.upper())
self.ionization_stage = int(ion)
self.charge_state = self.ionization_stage - 1
if hdf5_dbase_root is None:
self.hdf5_dbase_root = fiasco.defaults['hdf5_dbase_root']
else:
self.hdf5_dbase_root = hdf5_dbase_root
check_database(self.hdf5_dbase_root, **kwargs)
if self.ion_name not in fiasco.list_ions(self.hdf5_dbase_root,
sort=False):
raise MissingIonError(
f'{self.ion_name} not found in {self.hdf5_dbase_root}')
def extract_charge(arg: str):
"""
Receive a `str` representing an element, isotope, or ion.
Return a `tuple` containing a `str` that should represent an
element or isotope, and either an `int` representing the
charge or `None` if no charge information is provided. Raise
an `~plasmapy.particles.exceptions.InvalidParticleError` if charge information
is inputted incorrectly.
"""
invalid_charge_errmsg = (
f"Invalid charge information in the particle string '{arg}'.")
match = re.fullmatch(
r"\s*(?P<isotope>\w+(-[0-9]+)*([+-]*)*)"
r"(\s*(?P<charge>[+-]?[IVXLCDM0-9]+[+-]?)*)*\s*",
arg,
)
if match is None:
raise InvalidParticleError(invalid_charge_errmsg) from None
isotope_info = match.groupdict()["isotope"]
charge_info = match.groupdict()["charge"]
Z_from_arg = None
if charge_info is not None and isotope_info.endswith(("-", "+")):
# charge info is defined on both the charge_info and isotope_into strings
raise InvalidParticleError(invalid_charge_errmsg) from None
elif charge_info is not None: # Cases like 'H 1-' and 'Fe-56 1+'
sign_indicator_only_on_one_end = charge_info.endswith(
("-", "+")) ^ charge_info.startswith(("-", "+"))
just_one_sign_indicator = (charge_info.count("-") == 1
and charge_info.count("+")
== 0) or (charge_info.count("-") == 0
and charge_info.count("+") == 1)
if not sign_indicator_only_on_one_end and just_one_sign_indicator:
raise InvalidParticleError(invalid_charge_errmsg) from None
charge_str = charge_info.strip("+-")
try:
if roman.is_roman_numeral(charge_info):
Z_from_arg = roman.from_roman(charge_info) - 1
elif "-" in charge_info:
Z_from_arg = -int(charge_str)
elif "+" in charge_info:
Z_from_arg = int(charge_str)
else:
raise InvalidParticleError(invalid_charge_errmsg) from None
except ValueError:
raise InvalidParticleError(invalid_charge_errmsg) from None
elif isotope_info.endswith(("-", "+")): # Cases like 'H-' and 'Pb-209+++'
match = re.fullmatch(
r"\s*(?P<isotope>\w+(-[0-9]+)?)(?P<charge>[-+]+)\s*",
isotope_info,
)
isotope_info = match.groupdict()["isotope"]
charge_info = match.groupdict()["charge"]
if len(set(charge_info)) != 1:
raise InvalidParticleError(invalid_charge_errmsg) from None
Z_from_arg = len(charge_info)
if charge_info[0] == "-":
Z_from_arg = -Z_from_arg
return isotope_info, Z_from_arg
