Learn Python

Posts

Python File

File handling is the most important part of any Web Applications. This has several functions for creating, reading, updating, deleting files etc., File Handling: The key for working with files in Python is the open() function. Syntax: open(filename, mode) There are four different methods for opening a file: "r" - Read - Default value. Opens a file for reading, error if the file does not exist. "a" - Append - Opens a file for appending, creates the file if it does not exist. "w" - Write - Opens a file for writing, creates the file if it does not exist. "x" - Create - Creates the specified file, returns an error if the file exists. In addition you can specify if the file should be handled as binary or text mode: "t" - Text - Default value. Text mode. "b" - Binary - Binary mode(e.g., images) Note: Make sure the file exists, or else you will get an error. Syntax: f =

Program for Fibonacci numbers

The Fibonacci numbers are the numbers in the following integer sequence. 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, ……. In mathematical terms, the sequence Fn of Fibonacci num bers is defined by the recurrence relation Fn = Fn-1 + Fn-2 with seed values F0 = 0 and F1 = 1 Give a number n, print n-th Fibonacci Number. Input: n = 2 Output: 1 Input: n = 7 Output: 13 Write a function int fib(int n) that returns Fn. For example, if n = 0, then fib() should return 0. If n= 1, then it should return 1. For n > 1, it should return Fn-1 + Fn-2. Program: Method -1 (Use recursion) # Function for nth Fibonacci number def Fibonacci(n): if n< 0 : print ( "Incorrect input" ) # First Fibonacci number is 0 elif n = = 1 : return 0 # Second number is 1 Fibonacci elif n = = 2 : return 1 else : return Fibonacci(n - 1 ) + Fibonacci(n - 2

A small game created by me

A tiny game that is created using the following modules: Turtle Random Math Click the following link for the code: Torhungry-Game

5 Kind of Bugs Every Programmer Encounter During Coding

As a programmer, you have to expect bugs. In simple terms, a bug can be defined as an error in a program. During the coding of a program, we often make some mistakes. These mistakes showcase themselves as bugs in your code. Writing a code is the easy part. The hard step is the debugging (Searching for the errors or bugs in a program). And it can get especially frustrating in situations where you create more bugs instead of fixing the current one. If you haven’t encountered the following bugs, you should expect them any time soon: Tiny Bugs: These types of bugs may be miniature, but dealing with them is no easy task. You will receive compiler errors, and then spend hours, or even days trying to figure out where you went wrong. Such bugs include forgetting that little semicolon or bracket. In a programming language like Python, you can face trouble when indentation is wrongly done. Tiny bugs can be spotted when using the right IDE's. Little erro

Files I/O

Printing to the Screen: The simplest way to produce output is using the print statement where you can pass zero or more expressions separated by commas. This function converts the expressions you pass into a string and writes the result to standard output as follows − print " python is really a great language," This produces the following result on your standard screen - Python is really a great language, Reading Keyboard Input: Python provides two built-in functions to read a line of text from standard input, which by default comes from the keyboard. These functions are − raw_input input The raw_input Function: The raw_input([prompt]) function reads one line from standard input and returns it as a string (removing the trailing newline). Example: str = raw_input("Enter your input: ") print "Received input is: ", str This prompts you to enter any string and it would display same string on the screen. When I typed