[issue21253] unittest assertSequenceEqual can lead to Difflib.compare() crashing on mostly different sequences

Ernesto Eduardo Medina Núñez added the comment: While this gets fixed, can you provide a workaround? or recommend another library? -- nosy: +Ernesto Eduardo Medina Núñez ___ Python tracker

[issue21253] unittest assertSequenceEqual can lead to Difflib.compare() crashing on mostly different sequences

Change by Serhiy Storchaka : -- type: crash -> behavior versions: +Python 3.8 -Python 3.4, Python 3.5 ___ Python tracker ___ ___

[issue21253] unittest assertSequenceEqual can lead to Difflib.compare() crashing on mostly different sequences

Changes by Ivan Levkivskyi : -- versions: +Python 3.5, Python 3.6, Python 3.7 ___ Python tracker ___

[issue21253] unittest assertSequenceEqual can lead to Difflib.compare() crashing on mostly different sequences

John Taylor added the comment: I am seeing something similar in difflib.HtmlDiff.make_file() under Python 3.4.3 (windows 7). Do I need to file a separate bug report? File H:\test\test.py, line 522, in print_differ diff = html.make_file(file1_data,file2_data,dir 1,dir 2,True) File

[issue21253] unittest assertSequenceEqual can lead to Difflib.compare() crashing on mostly different sequences

Changes by Ivan Levkivskyi levkivs...@gmail.com: -- nosy: +levkivskyi ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue21253 ___ ___ Python-bugs-list

[issue21253] unittest assertSequenceEqual can lead to Difflib.compare() crashing on mostly different sequences

Gregory P. Smith added the comment: that seems reasonable. unittest's assertSequenceEqual is using this to attempt to display a useful error message as to what the delta was; it should try harder to avoid difflib corner cases. At the very least, unittest should recover from a difflib failure