omz:forum
    • Register
    • Login
    • Search
    • Recent
    • Popular

    Welcome!

    This is the community forum for my apps Pythonista and Editorial.

    For individual support questions, you can also send an email. If you have a very short question or just want to say hello — I'm @olemoritz on Twitter.

    If statement syntax error

    Pythonista
    7
    53
    11320
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • 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
                                        • OkieWolf
                                          OkieWolf last edited by

                                          Agreed. It works fine if short and long are the same number, which equals 45 degrees.

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

                                            Here’s what I came up with. It’s much shorter and easier to understand and I GREATLY appreciate all the help and patience.
                                            This version does all the other one did plus more. This version will calculate the other side and angle based on two sides input and can now calculate any side of the triangle based on angle and any one of the three sides.

                                            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)
	angle = float(v['angle'].text or 0)
	if len([x for x in (hypotenuse, short, long, angle) if x]) != 2:
		v['mess'].text = "Enter two fields"
		v['mess'].background_color = 'red'
		v['mess'].text_color = 'white'
		return
	if hypotenuse and not angle:
		if short and not long:
			v['long'].text = str(math.sqrt(hypotenuse ** 2 - short ** 2))
			v['long'].text_color = 'green'
			v['angle'].text = str(math.degrees(math.asin(short / hypotenuse)))
			v['angle'].text_color = 'green'
		elif long and not short:
			v['short'].text = str(math.sqrt(hypotenuse ** 2 - long ** 2))
			v['short'].text_color = 'green'
			v['angle'].text = str(math.degrees(math.acos(long / hypotenuse)))
			v['angle'].text_color = 'green'
	else:
		if not angle:
			v['hypotenuse'].text = str(math.sqrt(short ** 2 + long ** 2))
			v['hypotenuse'].text_color = 'green'
			v['angle'].text = str(math.degrees(math.atan(short / long)))
			v['angle'].text_color = 'green'
		
	if angle:
		angle = math.radians(angle)
		if short and not long and not hypotenuse:
			v['hypotenuse'].text = str(short / (math.sin(angle)))
			v['hypotenuse'].text_color = 'green'
			v['long'].text = str(short / (math.tan(angle)))
			v['long'].text_color = 'green'
		elif long and not short and not hypotenuse:
			v['hypotenuse'].text = str(long / (math.cos(angle)))
			v['hypotenuse'].text_color = 'green'
			v['short'].text = str(long * (math.tan(angle)))
			v['short'].text_color = 'green'
		elif angle and hypotenuse and not long and not short:
			v['short'].text = str(hypotenuse * (math.sin(angle)))
			v['short'].text_color = 'green'
			v['long'].text = str(hypotenuse * (math.cos(angle)))
			v['long'].text_color = 'green'
                                            1 Reply Last reply Reply Quote 0
                                            • First post
                                              Last post
                                            Powered by NodeBB Forums | Contributors