How to scroll the page in Appium + Python - appium

Question

I create tests using Appium+Python to test IOs app.
I want to scroll the page.
Here is the code
def scroll_page(self):
action = TouchAction(self)
action.press(BrowsePageElements.firs_element_to_scroll(self)).
move_to(BrowsePageElements.second_element_to_scroll(self)).perform()
When I'm trying to run this function, I get an error
error screenshot
Could you help me to find out, how to fix this error?

Answer 1

Appium Python has a native scroll function. It works for both Android and iOS.
driver.scroll(origin_el, destination_el, duration=None), where duration is an optional argument. This function scrolls origin_el to the location of destination_el.
Link to scroll source code
The Appium documentation is rather spotty and needs updating. However, the source code is documented well enough to understand and learn the program.

Answer 2

This currently works for me:
...
SCROLL_DUR_MS = 3000
...
window_size = self.driver.get_window_size()
self.scroll_y_top = window_size['height'] * 0.2
self.scroll_y_bottom = window_size['height'] * 0.8
self.scroll_x = window_size['width'] * 0.5
...
def scroll_up(self):
self._y_scroll(self.scroll_y_top, self.scroll_y_bottom)
def scroll_down(self):
self._y_scroll(self.scroll_y_bottom, self.scroll_y_top)
def _y_scroll(self, y_start, y_end):
actions = TouchAction(self.driver)
actions.long_press(None, self.scroll_x, y_start, SCROLL_DUR_MS)
actions.move_to(None, self.scroll_x, y_end)
actions.perform()
It scrolls slowly over 3s because I want it to be controlled, but you could shorten SCROLL_DUR_MS (the duration of the scroll action in milliseconds) if you want something more zoomy. I also went away from using elements as the start and/or end points because I wanted something general that would work with any screen content.
For scroll_y_top and scroll_y_bottom I picked 20% in from the top and bottom of the screen just to make sure I wasn't hitting anything at the borders (like the navigation bar at the top of iOS Preferences or an info bar at the bottom of the app I was working in). I also ran into a "bug" where it wasn't scrolling when I left scroll_x as 0, but it turns out that it wasn't registering the left edge as inside the scrolling area for the app I was working in.
Hope this helps.

Answer 3

In the past when i've run into issues scrolling for one reason or another, I've simply swiped using coordinates to scroll down the page.
self.driver.swipe(100, 700, 100, 150)