Fix python2 str() in visualization

[zjj]

refers to 3ed8f5f by timifasubaa

[codecov-io]

Codecov Report

Merging #5093 into master will not change coverage.
The diff coverage is 33.33%.

@@           Coverage Diff           @@
##           master    #5093   +/-   ##
=======================================
  Coverage   77.53%   77.53%           
=======================================
  Files          44       44           
  Lines        8710     8710           
=======================================
  Hits         6753     6753           
  Misses       1957     1957

Impacted Files	Coverage Δ
superset/viz.py	81.42% <33.33%> (ø)	⬆️

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[xrmx]

One nice way to fix these is by importing from builtins import str so that python2.7 will use str as unicode string instead of byte string.

[zjj]

I found this issue while using python2.7, don't use str here. actually, I think it's not right to use str() here even with python2.7, eg, utf8 bytes, chinese characters will raise exception. @xrmx

the origin patch was

-                series_title = [str(title) for title in name]
+                series_title = [title for title in name]
             elif isinstance(name, tuple):
-                series_title = tuple(str(title) for title in name)
+                series_title = tuple(title for title in name)
             else:
-                series_title = str(name)
+                series_title = name

and run gunicore with PYTHONIOENCODING="utf8" to fix that.

and I git log the history, found the refered commit. and that way seems easy for guys to handle.

[xrmx]

@zjj http://python-future.org/str_object.html

[zjj]

@xrmx
ah, I misunderstand your reply, I am not familiar with python3 and I doubt the origin patch that removed 'str()' would do something stupid with python3, so there comes the six.text_type for both python3 and python2.