Tutorial by Examples: io

The special attribute __name__ of a function, class or module is a string containing its name. import os class C: pass def f(x): x += 2 return x print(f) # <function f at 0x029976B0> print(f.__name__) # f print(C) # <class '__main__.C'> print(C.__name__...

Unlike Big-O notation, which represents only upper bound of the running time for some algorithm, Big-Theta is a tight bound; both upper and lower bound. Tight bound is more precise, but also more difficult to compute. The Big-Theta notation is symmetric: f(x) = Ө(g(x)) <=> g(x) = Ө(f(x)) An ...

Boolean logic expressions, in addition to evaluating to True or False, return the value that was interpreted as True or False. It is Pythonic way to represent logic that might otherwise require an if-else test. And operator The and operator evaluates all expressions and returns the last expressi...

Say we have the following tree: root - A - AA - AB - B - BA - BB - BBA Now, if we wish to list all the names of the elements, we could do this with a simple for-loop. We assume there is a function get_name() to return a string of the name of a node, a function get_children() t...

Detailed instructions on getting tomcat set up or installed.

SAS can be run in client-server model, using either the Enterprise Guide thick client or the SAS Studio thin (web-enabled) client, or in "local server" mode where a fully functional SAS system is present on a local machine (Windows or Unix/Linux desktop or server running in interactive mod...

HTML5 provides a new standard for embedding an audio file on a web page. You can embed an audio file to a page using the <audio> element: <audio controls> <source src="file.mp3" type="audio/mpeg"> Your browser does not support the audio element. </audi...

Swallowing Exceptions One should always re-throw exception in the following way: try { ... } catch (Exception ex) { ... throw; } Re-throwing an exception like below will obfuscate the original exception and will lose the original stack trace. One should never do this! The st...

Who says you cannot throw multiple exceptions in one method. If you are not used to playing around with AggregateExceptions you may be tempted to create your own data-structure to represent many things going wrong. There are of course were another data-structure that is not an exception would be mor...

$ react-native -v Example Output react-native-cli: 0.2.0 react-native: n/a - not inside a React Native project directory //Output from different folder react-native: react-native: 0.30.0 // Output from the react native project directory

In the app folder find package.json and modify the following line to include the latest version, save the file and close. "react-native": "0.32.0" In terminal: $ npm install Followed by $ react-native upgrade

Pass an open file object from Python to C extension code. You can convert the file to an integer file descriptor using PyObject_AsFileDescriptor function: PyObject *fobj; int fd = PyObject_AsFileDescriptor(fobj); if (fd < 0){ return NULL; } To convert an integer file descriptor back ...

Detailed instructions on Joomla installation can be found on its official website documentation.

Detailed instructions on getting joomla3.0 set up or installed.

Classpath requirements Eclipselink The Eclipselink and JPA API need to be included. Example Maven dependencies: <dependencies> <dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>eclipselink</artifactId> <version>2.6.3&lt...

Optional parameters can be specified after required parameters, by using &OPTIONAL keyword. There may be multiple optional parameters after it. (defun foobar (x y &optional z) (format t "X (~s) and Y (~s) are required.~@ Z (~s) is optional.~%" x y z)) ...

Global named functions are defined with DEFUN. (defun foobar () "Optional documentation string. Can contain line breaks. Must be at the beginning of the function body. Some will format the docstring so that lines are indented to match the first line, although the built-in DESCRIBE-func...

Functions always establish a block around the body. This block has the same name as the function name. This means you can use RETURN-FROM with this block name to return from the function and return values. You should avoid returning early whenever possible. (defun foobar (x y) (when (oddp x) ...

The search pattern can also be a regular expression. Running: grep '^[A-Z]' someFile.txt When someFile.txt contains: fred 14 m foo sam 68 m bar christina 83 f baz bob 22 m qux Sam 41 m quux Will produce the output: Sam 41 m quux since this is the only line in someFile.txt starting wi...

Scipy contains parts written in C, C++, and Fortran that need to be compiled before use. Therefore make sure the necessary compilers and Python development headers are installed. Having compiled code also means that Scipy needs additional steps to import from development sources, which are explained...