% is a string formatting operator or interpolation operator. Given format % values (where format is a string), % conversion specifications in format are replaced with zero or more elements of values. The effect is similar to using the sprintf() in the C language. For example, >>> lang = "Python" ... Read More

To convert string to bytes in Python 3, you can use the encode() function from the string class. For example,>>> s = u"HellΘ WΘrld" >>> s.encode('utf-8') 'Hell\xce\x98 W\xce\x98rld'

To parse a string to int, you can use the following:try:     print int('112') except ValueError:     print 'Cannot parse'This will give you the output:112To parse a string to float, you can use the following:try:     print float('112.15') except ValueError:     print 'Cannot parse'This will give ... Read More

The code can be written as follows to catch the exceptiona, b=5, 0 try:    if b != 0:        print a/b    else:        a/b        raise ZeroDivisionError except Exception as e:        print eWe get the following outputC:/Users/TutorialsPoint1/~.py integer division or modulo by zero

OSError serves as the error class for the os module, and is raised when an error comes back from an os-specific function.We can re-write the given code as follows to handle the exception and know its type.#foobar.py import os import sys try: for i in range(5): print i, os.ttyname(i) except ... Read More

The given code is rewritten to catch the exceptionimport sys import threading import time import Queue def thread(args1, stop_event, queue_obj): print "start thread" stop_event.wait(12) if not stop_event.is_set(): try: raise Exception("boom!") except Exception: queue_obj.put(sys.exc_info()) pass try: queue_obj = Queue.Queue() t_stop = threading.Event() t = threading.Thread(target=thread, args=(1, t_stop, queue_obj)) t.start() time.sleep(15) print ... Read More

In Python 3.x, the code is subject to exception chaining and we get the output as followsC:/Users/TutorialsPoint1/~.py Traceback (most recent call last): File "C:/Users/TutorialsPoint1/~.py", line 2, in 1/0 ZeroDivisionError: division by zeroThe above exception was the direct cause of the following exception:Traceback (most recent call last): File "C:/Users/TutorialsPoint1/~.py", line ... Read More

We can write custom exception classes with error codes and error messages as follows:class ErrorCode(Exception):     def __init__(self, code):         self.code = code     try:     raise ErrorCode(401) except ErrorCode as e:     print "Received error with code:", e.codeWe get outputC:/Users/TutorialsPoint1/~.py Received error ... Read More

During the handling of one exception ‘A’, it is possible that another exception ‘B’ may occur. In Python 2.0 versions, if this happens, exception B is propagated outward and exception A is lost. It is useful to know about both exceptions in order to debug the problem.Sometimes it is useful ... Read More

For the above module, we need to prepare following setup.py script −from distutils.core import setup, Extension setup(name='helloworld', version='1.0', \ ext_modules=[Extension('helloworld', ['hello.c'])])Now, we use the following command, $ python setup.py installOnce we install the extension, we would be able to import and call that extension in our Python script test.py and ... Read More