How to set opacity in text_clip using Lambda

[jitendra-koodo]

text_clip = text_clip.set_opacity(lambda t :   t/duration)

Is there any way to achieve this/make this work to change opacity from 0 to 1? Seems like Lambda is not allowed and I get following error :

File "E:\anaconda3\envs\moviepy\Lib\site-packages\decorator.py", line 232, in fun
    return caller(func, *(extras + args), **kw)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "E:\anaconda3\envs\moviepy\Lib\site-packages\moviepy\decorators.py", line 99, in add_mask_if_none
    return f(clip, *a, **k)
           ^^^^^^^^^^^^^^^^
  File "E:\anaconda3\envs\moviepy\Lib\site-packages\decorator.py", line 232, in fun
    return caller(func, *(extras + args), **kw)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "E:\anaconda3\envs\moviepy\Lib\site-packages\moviepy\decorators.py", line 14, in outplace
    f(newclip, *a, **k)
  File "E:\anaconda3\envs\moviepy\Lib\site-packages\moviepy\video\VideoClip.py", line 672, in set_opacity
    self.mask = self.mask.fl_image(lambda pic: op * pic)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "E:\anaconda3\envs\moviepy\Lib\site-packages\decorator.py", line 232, in fun
    return caller(func, *(extras + args), **kw)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "E:\anaconda3\envs\moviepy\Lib\site-packages\moviepy\decorators.py", line 14, in outplace
    f(newclip, *a, **k)
  File "E:\anaconda3\envs\moviepy\Lib\site-packages\moviepy\video\VideoClip.py", line 936, in fl_image
    arr = image_func(self.get_frame(0))
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "E:\anaconda3\envs\moviepy\Lib\site-packages\moviepy\video\VideoClip.py", line 672, in <lambda>
    self.mask = self.mask.fl_image(lambda pic: op * pic)
                                               ~~~^~~~~
TypeError: unsupported operand type(s) for *: 'function' and 'float'

[chenbin0522]

text_clip = text_clip.crossfadein(duration)