= Python Warts =

Python "warts" are things for which people have criticised Python, typically aspects of the language or mechanisms of its implementation, because such aspects either expose certain surprising inconsistencies, are regarded as omissions, or cause irritation for parts of the community in some sense. One goal of Python 3000 was to fix inconsistencies which could not have been fixed earlier due to the backwards compatibility constraints imposed on earlier releases of Python. This page summarises the unfixed warts, pitfalls and "gotchas" (which are not mere observations) from the following resources and lists Python 3000 remedies, if any:

 * Andrew Kuchling's [[http://web.archive.org/web/20031002184114/www.amk.ca/python/writing/warts.html|"Python Warts"]] - now archived
 * Hans Nowak's [[http://archive.is/xBOV2|"10 Python pitfalls"]] - now archived
 * Steven Ferg's [[http://web.archive.org/web/20080503031358/http://www.ferg.org:80/projects/python_gotchas.html|"Python Gotchas"]] - now archived
 * Mark Lutz's [[http://www.onlamp.com/pub/a/python/2004/02/05/learn_python.html|"When Pythons Attack"]] - [[http://archive.is/Tjd2q|Archive]]
 * David Mertz's "Python elegance and warts", [[http://web.archive.org/web/20090403002610/http://www.ibm.com/developerworks/linux/library/l-python-elegance-1.html|Part 1]] and [[http://archive.is/MdrIm|Part 2]] - now archived

In the table below, the following terminology is used:

 * No remedy: while some believe this to be a shortcoming, a lack of wider consensus has resulted in no remedy being pursued
 * Rejected: the shortcoming in question is regarded as a feature, typically because any attempt to remove it would arguably change the language in a way which would be even more confusing - see [[http://www.python.org/dev/peps/pep-3099/|PEP 3099]] for a list of such requested features

Note that the [[http://archive.is/c2tkF|"What's New in Python 3.0" document]] also contains a list of changes in Python 3000. One can argue that many of the changes are useful fixes that were too mundane for people to write critiques about.

||<#DDDDDD>'''Shortcoming''' ||<#EEEEEE> '''Source''' ||<#DDDDDD> '''Python 3000 Remedy''' ||
|| No do statement ||<#F0F0F0> Kuchling || ''No remedy'' ||
|| Local variables and scoping ||<#F0F0F0> Kuchling, Nowak, Lutz || ''No remedy'' ||
|| Calling base class methods ||<#F0F0F0> Kuchling || [[http://www.python.org/dev/peps/pep-3135/|New Super]] ||
|| Catching multiple exceptions ||<#F0F0F0> Kuchling, Nowak || [[http://www.python.org/dev/peps/pep-3110/|Catching Exceptions in Python 3000]] ||
|| Explicit self in methods ||<#F0F0F0> Kuchling || ''Rejected'' - this would require name declarations ||
|| Doubled underscores for private variables ||<#F0F0F0> Kuchling || ''No remedy'' ||
|| The .join() string method ||<#F0F0F0> Kuchling || ''No remedy'' ||
|| print >> ||<#F0F0F0> Kuchling || [[http://www.python.org/dev/peps/pep-3105/|Make print a function]] ||
|| Inconsistent indentation ||<#F0F0F0> Nowak || ''Rejected'' - indentation is central to Python's syntax ||
|| The += operator ||<#F0F0F0> Nowak || ''No remedy'' ||
|| Class attributes vs instance attributes ||<#F0F0F0> Nowak || ''No remedy'' ||
|| Mutable default arguments ||<#F0F0F0> Nowak, Ferg, Lutz || ''No remedy'' ||
|| [[http://web.archive.org/web/20161025191258/https://pythonconquerstheuniverse.wordpress.com/2008/06/04/gotcha-%E2%80%94-backslashes-are-escape-characters/|Backslashes are escape characters]] ||<#F0F0F0> Ferg || ''No remedy'' ||
|| [[http://web.archive.org/web/20080503031358/http://www.ferg.org:80/projects/python_gotchas.html#contents_item_4|Print and softspace]] ||<#F0F0F0> Ferg || [[http://www.python.org/dev/peps/pep-3105/|Make print a function]] ||
|| [[http://web.archive.org/web/20081029013232/http://pythonconquerstheuniverse.blogspot.com:80/2008/06/gotcha-forgetting-parentheses.html|Omitting parentheses when invoking a method]] ||<#F0F0F0> Ferg, Lutz || ''Rejected'' - taking a reference to a function/method is a feature ||
|| Imports and reloading ||<#F0F0F0> Lutz || ''No remedy'' - improved reloading has been considered ||
|| Inconsistent/unpredictable comparisons/ordering ||<#F0F0F0> Mertz || ''No remedy'' ||
|| Deficient sequence support for iterators, generators ||<#F0F0F0> Mertz || ''No remedy'' ||
|| Attribute access mechanism proliferation ||<#F0F0F0> Mertz || ''No remedy'' - Mertz suggests standard decorators ||