Moved from the educational wikis at http://coedit.net/ to here:

Common Problems Beginners Have

• The [http://www.alice.org/ Alice] 3D project developed a 3D programming environment for beginners. They used ["Python"] as the programming language originally (now switched to something else). There were two Python-specific issues that were problematic for beginners: the case-sensitivity of the language ("variable1" is not the same as "Variable1"), and integer division (a carryover from C, 3/4 = 0, not 0.75 because 0 is an integer and 0.75 is a float). The latter issue has been fixed, but the former has not and very likely never will. See this [http://www.linuxjournal.com/article.php?sid=5028 interview] in Linux Journal and this [http://www.alice.org/advancedtutorial/ConwayDissertation.PDF dissertation] for more details.

  • DougHolton is said to have patches to implement both of these features in the [http://boo.codehaus.org/ Boo] programming language, a language with similarities to Python, and they will appear in a release of Boo in the near future.

• This article ([http://www.onlamp.com/pub/a/python/2004/02/05/learn_python.html Common Mistakes of Python Programmers]) lists other common errors seen in Python training classes. Many result from the use of Python's interactive prompt and the IDLE text-based python development environment. Some of these problems might be solved by using IPython instead, but in general I never used (nor currently use) python's interactive prompt to develop applications.

• Another common error mentioned in the above article is forgetting to add a colon (:) at the end of if statements, class declarations, etc.

• Subtle errors which may cause some fairly difficult to follow messages happens when built-in type and function names are "shadowed" (ie. redefined). For example, using str as a variable name in a scope (ie. a function or class) will prevent the built-in function of the same name from being usable, producing an error like this: TypeError: 'str' object is not callable

• Even for advanced users there are features of the Python language that can cause difficulties. See [http://zephyrfalcon.org/labs/python_pitfalls.html 10 Python pitfalls], [http://web.archive.org/web/20031002184114/www.amk.ca/python/writing/warts.html Python Warts] and [http://www.ferg.org/projects/python_gotchas.html Python Gotchas]. These observations have in part been used to suggest refinements in future Python versions, notably Python 3000.

• Some ["Intermediate Conundrums"] have been noted with regard to the behaviour of some Python features, although these may be outside the scope of beginner problems.

Comments, Potential Solutions

• The [http://pychecker.sourceforge.net/ PyChecker] module can alert users to many common errors. There also is a tool called [http://www.logilab.org/projects/pylint PyLint].

• To see languages that have been used successfully with beginners and children, see Logo, !HyperTalk (used in HyperCard and SuperCard), HTML, JavaScript, variants of Basic, etc.

• Are students learning python to "learn programming" or to develop real applications? Does the IDLE interactive prompt help or hinder either? See http://developers.coedit.net/StudentsDevelopingEducationalSoftware for examples of students doing real application development and RapidPrototyping (although these are college students and in some cases CS majors who already know how to program).