def solve_equation(input):
assert type(input) == str
if Parser.is_equation(input):
equation = Parser.parse_equation(input)
variables = equation.get_variables()
if len(variables) != 1:
raise InputException(
'Equation should have exactly 1 variable but instead has {}: {}'
.format(str(len(variables)), variables))
result = Solver.single_variable(equation, variables[0])
else:
expression = Parser.parse_expression(input)
variables = expression.get_variables()
if len(variables) != 0:
raise InputException(
'Expression should have no variables but instead has the following: {}'
.format(variables))
result = expression.evaluate()
print(result)
