def is_arithmetic_expression(exp):
"""
Returns true if the string corresponds to an arithmetic expression, and false
otherwise
:param exp: the string to check
:return: true if the string is an arithmetic expression, false otherwise
"""
is_arithmetic_expression = False
cur_str = ''
for char_val in exp:
if char_val == '+' or char_val == '-' or char_val == '/' or (
char_val == '*' and len(exp) > 2):
is_arithmetic_expression = True
if char_val == '?' or char_val == '|' or char_val == '[' or char_val == '_' or char_val == "'":
return False
if char_val.isalpha():
cur_str += char_val
continue
if StringUtils.is_delimiter(char_val):
if cur_str not in MathExpression.fixed_functions:
return False
is_arithmetic_expression = True
cur_str = ''
return is_arithmetic_expression
def __init__(self, str_val):
if not isinstance(str_val, str):
raise NotImplementedError("UNDEFINED PARAMETERS")
"""
Creates a new string template.
:param str_val: the string object
"""
# the string corresponding to the template
self._str_val = str_val
# whether the string represents a whole word or phrase (and not a punctuation)
self._whole = len(str_val) != 1 or not StringUtils.is_delimiter(
str_val[0])
# empty set of slots
self._slots = set()
