Core Python Programming (2nd Edition)

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 easyto-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