If statement syntax error

[OkieWolf]

@ccc
Done

[ccc]

OK. Now it is time to separate the business logic from the UI representation. We would need to put all the math logic in a function of the form:

def triangle(a, b, hypotenuse=0, angle=45):
    pass  # math logic goes here

Where triangle(3, 4) returns (3, 4, 5.0, 45)
Where triangle(3, 0) would raise ValueError()

[JonB]

It seems to me you could also dispense with most of the long / short specific logic, and just compute the other edge, then figure out which one is the long vs short after the fact.

[OkieWolf]

@ccc

Please explain

def triangle(a, b, hypotenuse=0, angle=45):
    pass  # math logic goes here
Where triangle(3, 4) returns (3, 4, 5.0, 45)
Where triangle(3, 0) would raise ValueError() 

[ccc]

This was an invitation for you or someone else to write a function that can take between 2 and 4 parameters and calculate all other variables or raise an exception if there is no possible solution. This function would allow us to isolate all UI operations from all math operations. It would make it easier to test our math operations without the UI and would allow us to easily port the math operations to a different platform.

[OkieWolf]

@ccc

Below will calculate short and long with given hypotenuse and angle but you have to enter zero for short and long input.

import math

def triangle(short, long, hypotenuse, angle):
    pass  
    if hypotenuse and angle:
    	angle = math.radians(angle)
    	print ('Short = ' + str(hypotenuse * (math.sin(angle))))
    	print ('Long = ' + str(hypotenuse * (math.cos(angle))))
    	
triangle(0,0,10,30)

[OkieWolf]

@ccc

This will calculate any side or angle. But input still has to be zero for unknowns at input.

import math

def triangle(short, long, hypotenuse, angle):
    pass
    if len([x for x in (hypotenuse, short, long, angle) if x]) == 2:
    	if hypotenuse and angle:
    		angle = math.radians(angle)
    		print	('Short = ' + str(hypotenuse * (math.sin(angle))))
    		print	('Long = ' + str(hypotenuse * (math.cos(angle))))
    	elif long and angle:
    		angle = math.radians(angle)
    		print	('Short = ' + str(long * (math.tan(angle))))
    		print	('Hypotnuse = ' + str(long / (math.cos(angle))))
    	elif short and angle:
    		angle = math.radians(angle)
    		print	('Long = ' + str(short / (math.tan(angle))))
    		print	('Hypotnuse = ' + str(short / (math.sin(angle))))
    	elif hypotenuse and short:
    		print ('Long = ' + str(math.sqrt(hypotenuse ** 2 - short ** 2)))
    		print ('Angle = ' + str(math.degrees(math.asin(short / hypotenuse))))
    	elif hypotenuse and long:
    		print ('Short = ' + str(math.sqrt(hypotenuse ** 2 - long ** 2)))
    		print ('Angle = ' + str(math.degrees(math.acos(long / hypotenuse))))
    	elif short and long:
    		print ('Hypotenuse = ' + str(math.sqrt(short ** 2 + long ** 2)))
    		print ('Angle = ' + str(math.degrees(math.atan(short / long))))
    else:
    	print ("ERROR")

triangle(5,0,10,0) 

[ccc]

Step 0: drop the pass line.
Step 1:

    if len([x for x in (hypotenuse, short, long, angle) if x]) != 2:
        raise ValueError("Exactly two parameters must be zero.")

Step 2: change triangle() so it never prints but instead returns the answer with the statement return short, long, hypotenuse, angle
Step 3: change triangle(5,0,10,0) to print(triangle(5,0,10,0)).

Step 1: is called a fast-fail which is safer and more readable than failing later in the function. Basically is says "I see a bad situation (bad input data) so I am going to raise an exception and stop processing".

[mikael]

@ccc, I am sure I just saw you using count somewhere:

if (hyp, ...).count(0) != 2:
    raise ...

[OkieWolf]

@ccc

I don’t understand step 2

Step 2: change triangle() so it never prints but instead returns the answer with the statement return short, long, hypotenuse, angle.

Are you wanting me to change....
def triangle(short, long, hypotenuse, angle):

Also, changing to print(triangle(5,0,10,0)) adds “none” after returned values

[ccc]

def triangle(short, long, hypotenuse, angle):
    # Your code goes here...
    # Your code contains no print() calls.
    return short, long, hypotenuse, angle

[cvp]

Your code contains no print() calls, like

        if hypotenuse and angle:
            angle = math.radians(angle)
            short = hypotenuse * math.sin(angle)
            long  = hypotenuse * math.cos(angle) 

[OkieWolf]

@cvp

I still don’t know what you’re wanting. My code has many print calls.
Adding return short, long, hypotenuse, angle where you have it above won’t do anything because it’s part of the last elif. If I add it in line with def Tringle it errors.

import math

def triangle(short, long, hypotenuse, angle):
    pass
    if len([x for x in (hypotenuse, short, long, angle) if x]) == 2:
        if hypotenuse and angle:
            angle = math.radians(angle)
            print   ('Short = ' + str(hypotenuse * (math.sin(angle))))
            print   ('Long = ' + str(hypotenuse * (math.cos(angle))))
        elif long and angle:
            angle = math.radians(angle)
            print   ('Short = ' + str(long * (math.tan(angle))))
            print   ('Hypotnuse = ' + str(long / (math.cos(angle))))
        elif short and angle:
            angle = math.radians(angle)
            print   ('Long = ' + str(short / (math.tan(angle))))
            print   ('Hypotnuse = ' + str(short / (math.sin(angle))))
        elif hypotenuse and short:
            print ('Long = ' + str(math.sqrt(hypotenuse ** 2 - short ** 2)))
            print ('Angle = ' + str(math.degrees(math.asin(short / hypotenuse))))
        elif hypotenuse and long:
            print ('Short = ' + str(math.sqrt(hypotenuse ** 2 - long ** 2)))
            print ('Angle = ' + str(math.degrees(math.acos(long / hypotenuse))))
        elif short and long:
            print ('Hypotenuse = ' + str(math.sqrt(short ** 2 + long ** 2)))
            print ('Angle = ' + str(math.degrees(math.atan(short / long))))
    else:
        print ("ERROR")

triangle(5,0,10,0)  

[cvp]

@OkieWolf I understand, I only want to show what @ccc adviced. The triangle code without any print and only one print of triangle results

[OkieWolf]

@cvp

I think I understand now. But I can’t get the indentation at “return” to stop erroring.

import math

def triangle(short, long, hypotenuse, angle):
    if len([x for x in (hypotenuse, short, long, angle) if x]) != 2:
        raise ValueError("Exactly two parameters must be zero.")
    if hypotenuse and angle:
    	angle = math.radians(angle)
    	print	('Short = ' + str(hypotenuse * (math.sin(angle))))
    	print	('Long = ' + str(hypotenuse * (math.cos(angle))))
    elif long and angle:
    	angle = math.radians(angle)
    	print	('Short = ' + str(long * (math.tan(angle))))
    	print	('Hypotnuse = ' + str(long / (math.cos(angle))))
    elif short and angle:
    	angle = math.radians(angle)
    	print	('Long = ' + str(short / (math.tan(angle))))
    	print	('Hypotnuse = ' + str(short / (math.sin(angle))))
    elif hypotenuse and short:
    	print ('Long = ' + str(math.sqrt(hypotenuse ** 2 - short ** 2)))
    	print ('Angle = ' + str(math.degrees(math.asin(short / hypotenuse))))
    elif hypotenuse and long:
    	print ('Short = ' + str(math.sqrt(hypotenuse ** 2 - long ** 2)))
    	print ('Angle = ' + str(math.degrees(math.acos(long / hypotenuse))))
    elif short and long:
    	print ('Hypotenuse = ' + str(math.sqrt(short ** 2 + long ** 2)))
    	print ('Angle = ' + str(math.degrees(math.atan(short / long))))
  return(short, long, hypotenuse, angle)
    	
#triangle(5,0,10,0) 

[ccc]

from math import acos, asin, atan, cos, degrees, radians, sin, sqrt, tan


def triangle(short, long, hypotenuse=0, angle=0):
    if (hypotenuse, short, long, angle).count(0) != 2:
        raise ValueError("Exactly two parameters must be zero.")
    radians_angle = radians(angle)
    if short:
        if long:
            hypotenuse = sqrt(short ** 2 + long ** 2)
            angle = degrees(atan(short / long))
        elif hypotenuse:
            long = sqrt(hypotenuse ** 2 - short ** 2)
            angle = degrees(asin(short / hypotenuse))
        else:  # short and angle
            long = short / tan(radians_angle)
            hypotenuse = short / sin(radians_angle)
    elif long:
        if hypotenuse:
            short = sqrt(hypotenuse ** 2 - long ** 2)
            angle = degrees(acos(long / hypotenuse))
        else:  # long and angle
            short = long * tan(radians_angle)
            hypotenuse = long / cos(radians_angle)
    else:  # hypotenuse and angle
        short = hypotenuse * sin(radians_angle)
        long = hypotenuse * cos(radians_angle)
    short, long, hypotenuse = sorted([short, long, hypotenuse])
    return float(short), float(long), float(hypotenuse), float(angle)


# The result for each of these should be (3.0, 4.0, 5.0, 36.8698976458440x)
print(triangle(3, 4))  # short and long
print(triangle(3, 0, 5))  # short and hypotenuse
print(triangle(0, 4, 5))  # long and hypotenuse
print(triangle(0, 0, 5, 36.86989764584402))  # hypotenuse and angle

[ccc]

This post is deleted!

[cvp]

@ccc as short and long are différent, why do you think angle could be 45°?

[cvp]

@ccc error, you use angle instead of radians_angle

    else:  # hypotenuse and angle
        short = hypotenuse * sin(radians_angle)
        long = hypotenuse * cos(radians_angle) 

[ccc]

Thanks! Now you know why I failed trig back in the day...

Both issues fixed in the code above.