231 the java yardstick the java language environment

2.3.1 The Java Yardstick
The Java Language Environment White Paper [Gosling96] lists a number of desirable features of a program-
ming language:
• Simple and Familiar
• Object-Oriented
• Secure
• Interpreted
• Dynamic
• Architecture Neutral
• Portable
• Robust
• Multithreaded
• Garbage Collection
• Exceptions
16 Chapter 2. Background and History

Building Skills in Python, Release 2.6.5
• High Performance
Python meets and exceeds most of these expectations. We’ll look closely at each of these twelve desireable
attributes.
Simple and Familiar . By simple, we mean that there is no GOTO statement, we don’t need to explicitly
manage memory and pointers, there is no confusing preprocessor, we don’t have the aliasing problems
associated with unions. We note that this list summarizes the most confusing and bug-inducing features of
the C programming language.
Python is simple. It relies on a few core data structures and statements. The rich set of features is introduced
by explicit import of extension modules. Python lacks the problem-plagued GOTO statement, and includes
the more reliable break , continue and exception raise statements. Python conceals the mechanics of object
references from the programmer, making it impossible to corrupt a pointer. There is no language preprocessor
to obscure the syntax of the language. There is no C-style union (or COBOL-style REDEFINES) to create
problematic aliases for data in memory.
Python uses an English-like syntax, making it reasonably familiar to people who read and write English
or related languages. There are few syntax rules, and ordinary, obvious indentation is used to make the
structure of the software very clear.
Object-Oriented . Python is object oriented. Almost all language features are first class objects, and can be
used in a variety of contexts. This is distinct from Java and C++ which create confusion by having objects
as well as primitive data types that are not objects. The built-in type() function can interrogate the types of
all objects. The language permits creation of new object classes. It supports single and multiple inheritance.
Polymorphism is supported via run-time interpretation, leading to some additional implementation freedoms
not permitted in Java or C++.
Secure . The Python language environment is reasonably secure from tampering. Pre-compiled python
modules can be distributed to prevent altering the source code. Additional security checks can be added by
supplementing the built-in __import__() function.
Many security flaws are problems with operating systems or framework software (for example, database
servers or web servers). There is, however, one prominent language-related security problem: the “buffer
overflow” problem, where an input buffer, of finite size, is overwritten by input data which is larger than the
available buffer. Python doesn’t suffer from this problem.