http://www.devshed.com Python - RSS Feeds en-us Thu, 26 Nov 2009 09:36:01 -0500 Thu, 26 Nov 2009 09:36:01 -0500 Thu, 05 Feb 2009 09:00:46 -0500 http://www.devshed.com/c/a/Python/Tuples-and-Other-Python-Object-Types/?kc=rss - Missing Keys: if Tests One other note about dictionaries before we move on. Although we can assign to a new key to expand a dictionary, fetching a nonexistent key is still a mistake: gt; gt; gt; D gt; gt; gt; D['e'] = 99 # Assigning new keys grows d...]]> http://www.devshed.com/c/a/Python/Tuples-and-Other-Python-Object-Types/?kc=rss Thu, 29 Jan 2009 09:00:46 -0500 http://www.devshed.com/c/a/Python/The-Dictionary-Python-Object-Type/?kc=rss - List Comprehensions In addition to sequence operations and list methods, Python includes a more advanced operation known as a list comprehension expression, which turns out to be a powerful way to process structures like our matrix. Suppose, for instance, that we need to extract the second column ...]]> http://www.devshed.com/c/a/Python/The-Dictionary-Python-Object-Type/?kc=rss Thu, 22 Jan 2009 09:00:47 -0500 http://www.devshed.com/c/a/Python/String-and-List-Python-Object-Types/?kc=rss - Strings Strings are used to record textual information as well as arbitrary collections of bytes. They are our first example of what we call a sequence in Python that is, a positionally ordered collection of other objects. Sequences maintain a left-to-right order among the items they contain: thei...]]> http://www.devshed.com/c/a/Python/String-and-List-Python-Object-Types/?kc=rss Thu, 15 Jan 2009 09:00:46 -0500 http://www.devshed.com/c/a/Python/Introducing-Python-Object-Types/?kc=rss - This chapter begins our tour of the Python language. In an informal sense, in Python, we do things with stuff. “Things” take the form of operations like addition and concatenation, and “stuff” refers to the objects on which we perform those operations. In this part of the book, our focus is on that ...]]> http://www.devshed.com/c/a/Python/Introducing-Python-Object-Types/?kc=rss Mon, 29 Dec 2008 09:00:45 -0500 http://www.devshed.com/c/a/Python/Mobile-Programming-using-PyS60-Advanced-UI-Controls/?kc=rss - For complex interactions, advanced controls need to be used that can abstract out the complexities of the interaction to the user and provide a simple and consistent interface for the developer to work with. PyS60 has many such controls that a developer can use. In this discussion, the focus will ...]]> http://www.devshed.com/c/a/Python/Mobile-Programming-using-PyS60-Advanced-UI-Controls/?kc=rss Thu, 06 Nov 2008 09:00:46 -0500 http://www.devshed.com/c/a/Python/Nested-Functions-in-Python/?kc=rss - Namespaces A function's parameters, plus any variables that are bound (by assignment or by other binding statements, such as def) in the function body, make up the function's local namespace, also known as local scope. Each of these variables is known as a local variable of the function. Variabl...]]> http://www.devshed.com/c/a/Python/Nested-Functions-in-Python/?kc=rss Thu, 30 Oct 2008 09:00:46 -0400 http://www.devshed.com/c/a/Python/Python-Parameters-Functions-and-Arguments/?kc=rss - Parameters Formal parameters that are just identifiers indicate mandatory parameters. Each call to the function must supply a corresponding value (argument) for each mandatory parameter. In the comma-separated list of parameters, zero or more mandatory parameters may be followed by zero or more ...]]> http://www.devshed.com/c/a/Python/Python-Parameters-Functions-and-Arguments/?kc=rss Thu, 23 Oct 2008 09:00:46 -0400 http://www.devshed.com/c/a/Python/Python-Statements-and-Functions/?kc=rss - List comprehensions A common use of a for loop is to inspect each item in an iterable and build a new list by appending the results of an expression computed on some or all of the items. The expression form known as a list comprehension lets you code this common idiom concisely and directly. Since...]]> http://www.devshed.com/c/a/Python/Python-Statements-and-Functions/?kc=rss Thu, 16 Oct 2008 09:00:46 -0400 http://www.devshed.com/c/a/Python/Statements-and-Iterators-in-Python/?kc=rss - The print Statement A print statement is denoted by the keyword print followed by zero or more expressions separated by commas. print is a handy, simple way to output values in text form, mostly for debugging purposes. print outputs each expression x as a string that's just like the result of ca...]]> http://www.devshed.com/c/a/Python/Statements-and-Iterators-in-Python/?kc=rss Thu, 09 Oct 2008 09:00:45 -0400 http://www.devshed.com/c/a/Python/Sequences-and-Sets-in-Python/?kc=rss - Slicing a sequence To indicate a subsequence of S , you can use a slicing, with the syntax S[i:j], where i and j are integers. S[i:j] is the subsequence of S from the i th item, included, to the j th item, excluded. In Python, ranges always include the lower bound and exclude the upper bou...]]> http://www.devshed.com/c/a/Python/Sequences-and-Sets-in-Python/?kc=rss Thu, 02 Oct 2008 09:00:46 -0400 http://www.devshed.com/c/a/Python/Python-Expressions-and-Operators/?kc=rss - Expressions and Operators An expression is a phrase of code that Python evaluates to produce a value. The simplest expressions are literals and identifiers. You build other expressions by joining subexpressions with the operators and/or delimiters in Table 4-2. This table lists operators in decrea...]]> http://www.devshed.com/c/a/Python/Python-Expressions-and-Operators/?kc=rss Thu, 25 Sep 2008 09:00:46 -0400 http://www.devshed.com/c/a/Python/Dictionaries-Variables-and-Statements-in-Python/?kc=rss - Dictionaries A mapping is an arbitrary collection of objects indexed by nearly arbitrary values called keys. Mappings are mutable and, unlike sequences, are not ordered. Python provides a single built-in mapping type, the dictionary type. Library and extension modules provide other mapping type...]]> http://www.devshed.com/c/a/Python/Dictionaries-Variables-and-Statements-in-Python/?kc=rss Thu, 18 Sep 2008 09:00:46 -0400 http://www.devshed.com/c/a/Python/Data-Types-in-Python/?kc=rss - Data Types The operation of a Python program hinges on the data it handles. All data values in Python are objects, and each object, or value, has a type. An object's type determines which operations the object supports, or, in other words, which operations you can perform on the data value. The ty...]]> http://www.devshed.com/c/a/Python/Data-Types-in-Python/?kc=rss Thu, 11 Sep 2008 09:00:46 -0400 http://www.devshed.com/c/a/Python/The-Python-Language/?kc=rss - This chapter is a quick guide to the Python language. To learn Python from scratch, I suggest you start with Learning Python, by Mark Lutz and David Ascher (O'Reilly). If you already know other programming languages and just want to learn the specific differences of Python, this chapter is for you. ...]]> http://www.devshed.com/c/a/Python/The-Python-Language/?kc=rss Thu, 06 Mar 2008 09:00:54 -0500 http://www.devshed.com/c/a/Python/SSH-with-Twisted/?kc=rss - SSH, the Secure SHell, is an essential tool for many developers and administrators. SSH provides a way to establish encrypted, authenticated connections. The most common use of an SSH connection is to get a remote shell, but its possible to do many other things through SSH as well, including transfe...]]> http://www.devshed.com/c/a/Python/SSH-with-Twisted/?kc=rss