Section 1.7. Comparing Python

1.7. Comparing Python

Python has been compared with many languages. One reason is that it provides many features found in other languages. Another reason is that Python itself is derived from many other languages, including ABC, Modula-3, C, C++, Algol-68, SmallTalk, and Unix shell and other scripting languages, to name a few. Python is a virtual "greatest hits": van Rossum combined the features he admired most in the other languages he had studied and brought them together for our programming sanity.

However, more often than not, since Python is an interpreted language, you will find that most of the comparisons are with Perl, Java, Tcl, and JavaScript. Perl is another scripting language that goes well beyond the realm of the standard shell scripts. Like Python, Perl gives you the power of a full programming language as well as system call access.

Perl's greatest strength is in its string pattern matching ability, providing an extremely powerful regular expression matching engine. This has pushed Perl to become the de facto language for string text stream filtering, recognition, and extraction, and it is still the most popular language for developing Internet applications through Web servers' Common Gateway Interface (CGI). Python's regular expression engine is based significantly on Perl's.

However, Perl's obscure and overly symbolic syntax is much more difficult to decipher, resulting in a steep learning curve that inhibits the beginner, frustrating those for whom grasping concepts is impeded by semantics. This, coupled with Perl's "feature" of providing many ways of accomplishing the same task, introduces inconsistency and factionization of developers. Finally, all too often the reference book is required reading to decipher a Perl script that was written just a couple of months back.

Python is often compared to Java because of their similar OO nature and syntax. Java's syntax, although much simpler than C++'s, can still be fairly cumbersome, especially if you want to perform just a small task. Python's simplicity offers a much more rapid development environment than using just pure Java. One major evolution in Python's relationship with Java is the development of Jython, a Python interpreter written completely in Java. It is now possible to run Python programs with only the presence of a Java VM (virtual machine). We will mention more of Jython's advantages briefly in the following section, but for now we can tell you that in the Jython scripting environment, you can manipulate Java objects, Java can interact with Python objects, and you have access to your normal Java class libraries as if Java has always been part of the Python environment.

Python is now often compared to Ruby as well, due to the popularity of the Rails project. As we mentioned above, Python is a wider mix of multiple programming paradigms. It is not purely OO like Ruby and does not have Smalltalk-like blocks, perhaps Ruby's most distinguishable feature. Python does have a byte-code interpreter, where Ruby does not. Python is perhaps more readable, as Ruby can really be thought of as more of an OO Perl. With regard to Rails, Python has several own Web application frameworks, such as Django and Turbogears, to name two.

Tcl is another scripting language that shares similarities shares Python. Tcl is one of the first truly easy-to-use scripting languages to provide the programmer extensibility as well as system call access. Tcl is still popular today and perhaps somewhat more restrictive (due to its limited types) than Python, but it shares Python's ability to extend past its original design. More importantly, Tcl is often used with its graphical toolkit partner, Tk, in developing graphical user interface (GUI) applications. Due to its popularity, Tk has been ported to Perl (Perl/Tk) and Python (Tkinter). Also, it can be argued that Python's classes, modules, and packages make writing large programs in Python more pleasant than writing them in Tcl.

Python has some light functional programming (FP) constructs, which likens it to languages such as Lisp or Scheme. Although Python cannot be considered a traditional functional language, it continues to borrow features from languages such as Lisp and Haskell. For instance, list comprehensions were a welcome addition from the Haskell world, and Lisp programmers will feel at home with lambda, map, filter, and reduce.

JavaScript is another OO language very similar to Python. Any proficient JavaScript programmer will have little or no difficulty learning Python. The particularly astute reader will note that JavaScript is based on a prototype system, whereas Python follows a more traditional OO system that differentiates objects and classes.

Here is a list of some Web pages that have information on comparing or transitioning between Python and other languages:

Perl

http://www2.linuxjournal.com/article/3882

http://llama.med.harvard.edu/~fgibbons/PerlPythonPhrasebook.html

http://aplawrence.com/Unixart/pythonvsperl.html

http://pleac.sf.net/pleac_python

http://www.garshol.priv.no/download/text/perl.html

Java

http://dirtsimple.org/2004/12/python-is-not-java.html

http://twistedmatrix.com/users/glyph/rant/python-vs-java.html

http://netpub.cstudies.ubc.ca/oleary/python/python_java_comparison.php

Lisp

http://strout.net/python/pythonvslisp.html

http://norvig.com/python-lisp.html

Ruby

http://blog.ianbicking.org/ruby-python-power.html

http://www.rexx.com/~oinkoink/Ruby_v_Python.html

http://dev.rubycentral.com/faq/rubyfaq-2.html

Perl, C++

http://strombergers.com/python/

Perl, Java, C++

http://furryland.org/~mikec/bench/

C++, Java, Ruby

http://dmh2000.com/cjpr

Perl, Java, PHP, Tcl

http://www-128.ibm.com/developerworks/linux/library/l-python101.html

http://www-128.ibm.com/developerworks/linux/library/l-script-survey/

C, C++, Java, Perl, Rexx, Tcl

http://www.ubka.uni-karlsruhe.de/indexer-vvv/ira/2000/5

You can access a number of other comparisons between Python and other languages at:

http://www.python.org/doc/Comparisons.html