You can find Editorial under the action group 'Apps', if you have installed Editorial.

You can Send the App Store link to Apples Shortcut -> Editorial Workflow.

From there you have Python to do what you want.

Hi, @OkieWolf

You can post your Code with the top right button in the forum Editor.
</>
This result in better formatting Code.

To debug your Code:
Close your UI View and click the right Button where you see the Errormessage.

Then click on Variables

There you can see that ang and rad are strings.
You can also set Breakpoints by tap and Hold within the Editor.
Or you can use a print command: print(type(rad))

You only need to convert them to float. And the Result back to string

arc = str(float(rad) * float(ang) * pi / 180)

Edit: See you solve your Problem

@OkieWolf, I think @mikael is write. You can do it with the pyui Editor too.

You need also change the order of your Pythoncode (def needs to be before the main Program).

import ui
import math

def button1_tapped(sender):
    rad = sender.superview['textfield1'].text
    ang = sender.superview['textfield2'].text
    pi = math.pi
    sender.superview['label1'].text = rad
    
    
v = ui.load_view()
v.present('sheet')

Did you set button.action?
Here is a quick + dirty Example in Pythonista

import ui
import math

class cUIView(ui.View):
    def __init__(self):
        self.name = 'Title'
        self.width = 300
        self.height = 200

        self.lbl01 = self.makeLabels('angle')
        self.lbl02 = self.makeLabels('radius')
        self.lbl03 = self.makeLabels('arc length')
        self.txtView01 = self.makeTextview()
        self.txtView02 = self.makeTextview()
        self.txtView03 = self.makeTextview()
        self.btn01 = self.makeButtons('btn01')
        
        self.style()

    def layout(self):
        # layout of the ui.view, will be called when a view is resized
        self.lbl01.frame = (10, 10, 100, 40)
        self.lbl02.frame = (150, 10, 100, 40)
        self.lbl03.frame = (10, 100, 100, 40)
        self.txtView01.frame = (10, 50, 100, 40)
        self.txtView02.frame = (150, 50, 100, 40)
        self.txtView03.frame = (10, 140, 100, 40)
        self.btn01.frame = (150, 100, 100, 40)

    def style(self):
        # the view style
        self.background_color = 'lightgrey'
        self.txtView01.text = str(1.5)
        self.txtView02.text = str(10)

    def makeButtons(self, vName):
        vButton = ui.Button()
        vButton.name = vName
        vButton.title = vName
        vButton.border_width = 1
        vButton.action = self.btnAction
        self.add_subview(vButton)
        return vButton

    def makeLabels(self, vName):
        vLabel = ui.Label()
        vLabel.name = vName
        vLabel.text = vName
        vLabel.border_width = 1
        vLabel.alignment = ui.ALIGN_CENTER
        self.add_subview(vLabel)
        return vLabel

    def makeTextview(self):
        vTxtView = ui.TextView()
        vTxtView.border_width = 1
        self.add_subview(vTxtView)
        return vTxtView

    def btnAction(self, vSender):
        if vSender.name == self.btn01.name:
            pi = math.pi
            angle = float(self.txtView01.text)
            radius = float(self.txtView02.text)
            arc = radius * angle * pi / 180
            self.txtView03.text = str(arc)

if __name__ == '__main__':
    vView = cUIView()
    vView.present('sheet')

or tap and hold space

@DaricLiu ,
Try to reboot your device.
We have discussed this: see here

And i found out, it isn't the same Path twice. If you move the Script, it is old Path and new Path.

There is also a system wide Clipboard:
Use Universal Clipboard to copy and paste between your Apple devices

(doesnt help here, but i found it interest to know)

@dougler1, or send a screenshot, so we know where you are within your Pythonista.

To send a screenshot you can use:
-and-
https://imgur.com/

@Drizzel, you could be right about iPadOS i test it at my iPhone with iOS 12.4.5 and then 12.4.6 and it works. There is also no popup.

About the german one, nobody should know about this, before the stupid one (me) send a screenshot 🤫