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    If statement syntax error

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    • mcriley821
      mcriley821 @OkieWolf last edited by mcriley821

      @OkieWolf
      To specify hex you have to have a # in front

      red = '#ff0000'

      The current hex value you have is mostly white. It’s also too long. 'red' should work too

      OkieWolf 1 Reply Last reply Reply Quote 0
      • OkieWolf
        OkieWolf @mcriley821 last edited by

        @mcriley821
        Still doesn’t change

        mcriley821 1 Reply Last reply Reply Quote 0
        • mcriley821
          mcriley821 @OkieWolf last edited by

          @OkieWolf then it’s not making it to the else statement. What are you inputting to the textfields? Maybe one of them is white space?

          OkieWolf 1 Reply Last reply Reply Quote 0
          • OkieWolf
            OkieWolf @mcriley821 last edited by

            @mcriley821
            It’s getting to the else statement because it’s inputting the text “Enter All Fields”. It just won’t change the color.

            cvp mikael 2 Replies Last reply Reply Quote 0
            • mcriley821
              mcriley821 last edited by

              @OkieWolf

              Scratch that, sorry. I was thinking of a label. A textField doesn’t really have a background. It’s background is behind the white layer. What you could do instead is make a red border.

              If you really want the whole thing red, I can write a small bit of code with objc_util

              1 Reply Last reply Reply Quote 0
              • cvp
                cvp @OkieWolf last edited by

                @OkieWolf already done here

                1 Reply Last reply Reply Quote 1
                • mikael
                  mikael @OkieWolf last edited by

                  @OkieWolf, you hit one of known quirks. You can set bordered to False, after which background_color works. Or if that appearance does not work for you, @cvp’s solution can be turned into a helper function that you can call with just 'red':

                  def textfield_background(tf, color):
    import objc_util
    tfo = tf.objc_instance.textField()
    tfo.backgroundColor = objc_util.UIColor.colorWithRed_green_blue_alpha_(
        *ui.parse_color(color))
                  OkieWolf 1 Reply Last reply Reply Quote 0
                  • OkieWolf
                    OkieWolf last edited by

                    What about text color? Can I change the textfield text color to red?

                    cvp 1 Reply Last reply Reply Quote 0
                    • cvp
                      cvp @OkieWolf last edited by

                      @OkieWolf .text_color = 'red'

                      1 Reply Last reply Reply Quote 0
                      • OkieWolf
                        OkieWolf @mikael last edited by

                        This post is deleted!
                        1 Reply Last reply Reply Quote 0
                        • OkieWolf
                          OkieWolf last edited by OkieWolf

                          Here’s the completed button using the Pythagorean Theorem to calculate. It looks to see which of the three textfields is blank then calculates what it should be based on the input of the other two.

                          def button3_tapped(sender):
	if (v['textfield3'].text)!="" and (v['textfield4'].text)!="":
		hyp = float(v['textfield3'].text)
		sht = float(v['textfield4'].text)
		hyp = pow(hyp,2)
		sht = pow(sht,2)
		lng = math.sqrt(hyp - sht)
		v['textfield5'].text_color = 'green'
		v['textfield5'].text = str(lng)
	elif (v['textfield4'].text)!="" and (v['textfield5'].text)!="":
		sht = float(v['textfield4'].text)
		lng = float(v['textfield5'].text)
		sht = pow(sht,2)
		lng = pow(lng,2)
		hyp = math.sqrt(sht + lng)
		v['textfield3'].text_color = 'green'
		v['textfield3'].text = str(hyp)
	elif (v['textfield3'].text)!="" and (v['textfield5'].text)!="":
		hyp = float(v['textfield3'].text)
		lng = float(v['textfield5'].text)
		hyp = pow(hyp,2)
		lng = pow(lng,2)
		sht = math.sqrt(hyp - lng)
		v['textfield4'].text_color = 'green'
		v['textfield4'].text = str(sht)
	else:
		v['textfield5'].text_color = 'red'
		v['textfield5'].text = 'ENTER ALL FIELDS' ```
                          1 Reply Last reply Reply Quote 1
                          • ccc
                            ccc last edited by ccc

                            The logic is easier to follow if field names describe their content.

                            def button3_tapped(sender):
    hypotenuse = float(v['hypotenuse'].text or 0)
    short = float(v['short'].text or 0)
    long = float(v['long'].text or 0)
    if len([x for x in (hypotenuse, short, long) if x]) != 2:
        v['long'].text = "Enter floats in 2 fields"
        v['long'].text_color = 'red'
        return
    if hypotenuse:
        if short and not long:
            v['long'].text = str(math.sqrt(hypotenuse ** 2 - short ** 2))
            v['long'].text_color = 'green'
        elif long and not short:
            v['short'].txt = str(math.sqrt(hypotenuse ** 2 - long ** 2))
            v['short'].text_color = 'green'
    else:
        v['hypotenuse'].text = str(math.sqrt(short ** 2 + long ** 2))
        v['hypotenuse'].text_color = 'green'
                            OkieWolf 1 Reply Last reply Reply Quote 0
                            • OkieWolf
                              OkieWolf @ccc last edited by OkieWolf

                              @ccc
                              Could you please explain how this works in more detail?
                              I realize you’ve renamed textfields but I’m not exactly understanding how the code is working. I’m mainly not understanding what’s happening with the or 0 and then the if len([x for x in (hypotenuse, short, long) if x]) != 2

                              hypotenuse = float(v['hypotenuse'].text or 0)
    short = float(v['short'].text or 0)
    long = float(v['long'].text or 0)
    if len([x for x in (hypotenuse, short, long) if x]) != 2: ```
                              mcriley821 1 Reply Last reply Reply Quote 0
                              • mcriley821
                                mcriley821 @OkieWolf last edited by ccc

                                @OkieWolf

                                hypotenuse = float(v['hypotenuse'].text or 0)
    short = float(v['short'].text or 0)
    long = float(v['long'].text or 0)
    if len([x for x in (hypotenuse, short, long) if x]) != 2: ```

                                v['short'].text or 0 will choose 0 if the text is "". You won’t hit an exception for a blank textfield. You will get an error if the text is alphabetical though.

                                (hypotenuse,short,long) is a tuple and [x for x in (hypotenuse,short,long) if x] is a list comprehension that steps through the tuple
                                and makes a list of the values that exist. Then if the length of that list isn’t 2, then you don’t have a correct input

                                1 Reply Last reply Reply Quote 0
                                • OkieWolf
                                  OkieWolf last edited by

                                  I need to probably rewrite the whole program because I’ve added more error trapping and a fourth textfield. It has increased complexity quite a bit, at least for me. It now cycles through all four textfields, find any two valid fields, decides whether to use Pythagorean Theorem or plain trig, and checks all for errors. One error in particular is that it is possible with the answers to have the short side of the triangle be longer than the long side. Obviously this can never happen so it’s now trapped and alerts the user.
                                  Below is what I now have. I realize my code is a longer than it needs to be and fairly cumbersome at this point but I’m just learning Python and intend to try to rewrite it in a better and more efficient way.

                                  def button3_tapped(sender):
	if (v['textfield3'].text)!="" and (v['textfield4'].text)!="":
		v['label7'].background_color = 'white'
		v['label7'].text_color = 'white'
		v['label7'].text = ''
		hyp = float(v['textfield3'].text)
		sht = float(v['textfield4'].text)
		hypa = hyp
		shta = sht
		hyp = pow(hyp,2)
		sht = pow(sht,2)
		lng = math.sqrt(hyp - sht)
		lnga = lng
		ang = math.asin(shta/hypa)
		ang = math.degrees(ang)
		v['textfield5'].text_color = 'green'
		v['textfield5'].text = str(lng)
		v['textfield6'].text_color = 'green'
		v['textfield6'].text = str(ang)
		shtb = float(v['textfield4'].text)
		lngb = float(v['textfield5'].text)
		if shtb > lngb:
			v['label7'].background_color = 'red'
			v['label7'].text_color = 'white'
			v['label7'].text = 'ERROR. Short side cannot be longer than long side.'
	elif (v['textfield4'].text)!="" and (v['textfield5'].text)!="":
		v['label7'].background_color = 'white'
		v['label7'].text_color = 'white'
		v['label7'].text = ''
		sht = float(v['textfield4'].text)
		shta = sht
		lng = float(v['textfield5'].text)
		lnga = lng
		sht = pow(sht,2)
		lng = pow(lng,2)
		hyp = math.sqrt(sht + lng)
		hypa = hyp
		ang = math.asin(shta/hypa)
		ang = math.degrees(ang)
		v['textfield3'].text_color = 'green'
		v['textfield3'].text = str(hyp)
		v['textfield6'].text_color = 'green'
		v['textfield6'].text = str(ang)
		shtb = float(v['textfield4'].text)
		lngb = float(v['textfield5'].text)
		if shtb > lngb:
			v['label7'].background_color = 'red'
			v['label7'].text_color = 'white'
			v['label7'].text = 'ERROR. Short side cannot be longer than long side.'
	elif (v['textfield3'].text)!="" and (v['textfield5'].text)!="":
		v['label7'].background_color = 'white'
		v['label7'].text_color = 'white'
		v['label7'].text = ''
		hyp = float(v['textfield3'].text)
		hypa = hyp
		lng = float(v['textfield5'].text)
		lnga = lng
		hyp = pow(hyp,2)
		lng = pow(lng,2)
		sht = math.sqrt(hyp - lng)
		shta = sht
		ang = math.asin(shta/hypa)
		ang = math.degrees(ang)
		v['textfield4'].text_color = 'green'
		v['textfield4'].text = str(sht)
		v['textfield6'].text_color = 'green'
		v['textfield6'].text = str(ang)
		shtb = float(v['textfield4'].text)
		lngb = float(v['textfield5'].text)
		if shtb > lngb:
			v['label7'].background_color = 'red'
			v['label7'].text_color = 'white'
			v['label7'].text = 'ERROR. Short side cannot be longer than long side.'
	elif (v['textfield3'].text)!="" and (v['textfield6'].text)!="":
		v['label7'].background_color = 'white'
		v['label7'].text_color = 'white'
		v['label7'].text = ''
		hyp = float(v['textfield3'].text)
		ang = float(v['textfield6'].text)
		ang = math.radians(ang)
		hypa = hyp
		sht = hyp * math.sin(ang)
		shta = sht
		hypc = pow(hyp,2)
		shtc = pow(sht,2)
		lng = math.sqrt(hypc - shtc)
		lnga = lng
		v['textfield5'].text_color = 'green'
		v['textfield5'].text = str(lng)
		v['textfield4'].text_color = 'green'
		v['textfield4'].text = str(sht)
		shtb = float(v['textfield4'].text)
		lngb = float(v['textfield5'].text)
		if shtb > lngb:
			v['label7'].background_color = 'red'
			v['label7'].text_color = 'white'
			v['label7'].text = 'ERROR. Short side cannot be longer than long side.'
	elif (v['textfield4'].text)!="" and (v['textfield6'].text)!="":
		v['label7'].background_color = 'white'
		v['label7'].text_color = 'white'
		v['label7'].text = ''
		sht = float(v['textfield4'].text)
		ang = float(v['textfield6'].text)
		ang = math.radians(ang)
		shta = sht
		hyp = sht / math.sin(ang)
		hypa = hyp
		hypc = pow(hyp,2)
		shtc = pow(sht,2)
		lng = math.sqrt(hypc - shtc)
		shta = sht
		v['textfield5'].text_color = 'green'
		v['textfield5'].text = str(lng)
		v['textfield3'].text_color = 'green'
		v['textfield3'].text = str(hyp)
		shtb = float(v['textfield4'].text)
		lngb = float(v['textfield5'].text)
		if shtb > lngb:
			v['label7'].background_color = 'red'
			v['label7'].text_color = 'white'
			v['label7'].text = 'ERROR. Short side cannot be longer than long side.'
	elif (v['textfield5'].text)!="" and (v['textfield6'].text)!="":
		v['label7'].background_color = 'white'
		v['label7'].text_color = 'white'
		v['label7'].text = ''
		lng = float(v['textfield5'].text)
		ang = float(v['textfield6'].text)
		ang = math.radians(ang)
		lnga = lng
		hyp = lng / math.cos(ang)
		hypa = hyp
		hypc = pow(hyp,2)
		lngc = pow(lng,2)
		sht = math.sqrt(hypc - lngc)
		shta = sht
		v['textfield4'].text_color = 'green'
		v['textfield4'].text = str(sht)
		v['textfield3'].text_color = 'green'
		v['textfield3'].text = str(hyp)
		shtb = float(v['textfield4'].text)
		lngb = float(v['textfield5'].text)
		if shtb > lngb:
			v['label7'].background_color = 'red'
			v['label7'].text_color = 'white'
			v['label7'].text = 'ERROR. Short side cannot be longer than long side.'
	else:
		v['label7'].background_color = 'red'
		v['label7'].text_color = 'white'
		v['label7'].text = 'ERROR' ```
                                  1 Reply Last reply Reply Quote 0
                                  • OkieWolf
                                    OkieWolf last edited by

                                    If you import math why do you still have to say math.sqrt and math.cos?
                                    But then other things like pow don’t have to say math.pow.

                                    1 Reply Last reply Reply Quote 0
                                    • ccc
                                      ccc last edited by

                                      pow() is a Python builtin. https://docs.python.org/3/library/functions.html

                                      You can also say from math import cos, sin, tan to use the single word functions.

                                      OkieWolf 1 Reply Last reply Reply Quote 0
                                      • OkieWolf
                                        OkieWolf last edited by

                                        This post is deleted!
                                        1 Reply Last reply Reply Quote 0
                                        • OkieWolf
                                          OkieWolf @ccc last edited by OkieWolf

                                          @ccc

                                          I’m attempting to rewrite my code to be more efficient and am utilizing a couple of code snippets that a couple of you have supplied. However, in the below code I noticed that the output is 0.0 if both inputs happen to be the same number. I’m not understanding why.

                                          def button3_tapped(sender):
	hypotenuse = float(v['hypotenuse'].text or 0)
	short = float(v['short'].text or 0)
	long = float(v['long'].text or 0)
	if len([x for x in (hypotenuse, short, long) if x]) != 2:
		v['mess'].text = "Enter two fields"
		v['mess'].background_color = 'red'
		v['mess'].text_color = 'white'
		return
	if hypotenuse:
		if short and not long:
			v['long'].text = str(math.sqrt(hypotenuse ** 2 - short ** 2))
			v['long'].text_color = 'green'
		elif long and not short:
			v['short'].text = str(math.sqrt(hypotenuse ** 2 - long ** 2))
			v['short'].text_color = 'green'
	else:
		v['hypotenuse'].text = str(math.sqrt(short ** 2 + long ** 2))
		v['hypotenuse'].text_color = 'green' ```
                                          1 Reply Last reply Reply Quote 0
                                          • ccc
                                            ccc last edited by ccc

                                            if both inputs happen to be the same number

                                            if hypotenuse:
    if short:
        The rules of math say that the hypotenuse must be greater than short.
    else
        The rules of math say that the hypotenuse must be greater than long.
else:
    short could be the same number as long  # <-- this is the only instance where both inputs could be the same number

                                            if hypotenuse and (short >= hypotenuse or long >= hypotenuse):
    raise ValueError("Not allowed by the rules of math.")
                                            1 Reply Last reply Reply Quote 0
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