if args_length == 0:
print("Please enter your funtion arguments")
continue
print("Answer: " + str(user_equation.solveEquation(args)))
args = []
elif user_input == 'r':
print()
print("Arguments Reset")
args = []
elif user_input == 'd':
print()
user_equation.args = ['1', '0', '+', '5' ,'*', '2', '/', '5', '-', '1', '1']
user_equation.setup()
print("Answer :" + str(user_equation.solve()))
elif user_input == 'e':
print()
num_of_operators = randint(1,4)
for i in range(num_of_operators):
digits = randint(1,3)
for j in range(digits):
args.append(str(randint(0,9)))
symbol_index = randint(10,13)
args.append(symbol_inputs[symbol_index])
digits = randint(1,3)
for j in range(digits):
args.append(str(randint(0,9)))
print("Answer: " + str(user_equation.solveEquation(args)))
args = []
def evaluate_infix(expression):
"""
The highest level function for evaluation of expressions
:param expression: string representing an infix expression
:return: err_start, err_end, message, interpreted expression in case of any error,
None, None, solution, interpreted_expression otherwise
"""
pat_unallowed = re.compile(r'([^A-Za-z0-9+\-*/=.,\s()])')
if len(pat_unallowed.findall(expression)) > 0:
pos = next(pat_unallowed.finditer(expression)).start()
return pos, pos, "Unallowed symbol detected: %s" % expression[
pos], expression
if "=" in expression: # Solve an equation
if expression.count("=") > 1:
pos = expression.index("=") + expression[expression.index("=") +
1:].index("=") + 1
return pos, pos, "More than one '=' symbols in expression can't be interpreted", expression
result = Equations.solve(*expression.split("="))
if len(result) == 4:
return result
else:
try:
varname = result[0]
polynomial = result[1]
interpreted_expression = result[2]
except (TypeError, IndexError):
return -1, -1, "Something has gone terribly wrong", expression
else:
postfix_expression = PostfixExpression(expression)
interpreted_expression = postfix_expression.interpreted_expression
if postfix_expression.error_msg is not None:
pos = postfix_expression.error_place
return pos[0], pos[
1], postfix_expression.error_msg, interpreted_expression
else:
varname = ""
polynomial = postfix_expression.result.polynomial
solver = PolynomialSolver()
try:
# Take the first (and the only) solution
result = solver.solve(polynomial)[0]
except NotImplementedError as e:
return -1, -1, e.args[0], expression
if result[1] == 0:
if '=' in expression:
return -1, -1, "The expression doesn't have a variable " + \
"(or the coefficient before it is 0), but " + \
"has a '=' sign. It cannot be interpreted.", expression
# Formatting the result
num_result = result[0] if math.floor(
result[0]) != result[0] else math.floor(result[0])
return None, None, str(num_result), interpreted_expression
else:
if '=' not in expression:
return -1, -1, "The expression has variables but doesn't have '=' sign." + \
"Should it be treated as equation?", expression
# Formatting the result
num_result = result[0] if math.floor(
result[0]) != result[0] else math.floor(result[0])
return None, None, varname + ' = ' + str(
num_result), interpreted_expression
