pyqtgraph.python2_3 no longer exists

[sapols]

On line 6 of AxisItem.py you are importing:
from pyqtgraph.python2_3 import asUnicode

but pyqtgraph.python2_3 no longer exists in the current version of pyqtgraph (0.12.3). Since your requirements.txt specifies pyqtgraph >= 0.11.1, a normal import of pytplot now fails because dependency resolution will simply get the latest pyqtgraph and python2_3.py won't exist in it.

Either requirements.txt should be changed to specify a pyqtgraph version lower than 0.12.3 or AxisItem should be changed to not require pyqtgraph.python2_3. The latter is probably preferable since everyone's dropping Python 2 support.

[JeffreyBroll]

Further, since Python 3 all strings have been Unicode anyway - the function being imported just made sure the argument was encoded as a UTF-8 string

• if python 2 encode ASCII string (or cast any non-string) into UTF-8
• if python 3 cast to string (which is already Unicode)
  So python2 support can be maintained by cloning this, and if python2 support isn't of continued interest asUnicode can be replaced by str (or removed if the list 'strings' is absolutely always full of strings).
  asUnicode.txt

[AlimyBreak]

pip install pyqtgraph==0.11.1

[STBadman]

Hi, just wanted to ping that I was caught out by this same issue just now when upgrading pytplot to version 1.7.28 in response to spedas/pyspedas#434

I was prompted to install pyqtgraph and initially installed the latest version (0.13.2), for which the submodule python2_3 doesn't exists. I downgraded as above so it works now, but would be preferable for this not be called in pyspedas.