From c996b79a9f301d2c1b5bd3b183195b12bcac63a1 Mon Sep 17 00:00:00 2001 From: Rishab Kumar <45825464+rishabkumar7@users.noreply.github.com> Date: Mon, 13 Feb 2023 22:26:16 -0500 Subject: [PATCH] Update day43.md --- 2023/day43.md | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) diff --git a/2023/day43.md b/2023/day43.md index e69de29..c769f98 100644 --- a/2023/day43.md +++ b/2023/day43.md @@ -0,0 +1,114 @@ +# Day 43 - Programming Language: Python + +Welcome to the second day of Python, and today we will cover some more concepts: +- Loops +- Functions +- Modules and libraries +- File I/O + +## Loops (for/while): + +Loops are used to repeatedly run a block of code. + +### for loop + +Using the `for` loop, a piece of code is executed once for each element of a sequence (such as a list, string, or tuple). Here is an example of a for loop that prints each programming language in a list: + +``` python +languages = ['Python', 'Go', 'JavaScript'] + +# for loop +for language in languages: + print(language) +``` + +Output +``` +Python +Go +JavaScript +``` + +### while loop + +The `while loop` is used to execute a block of code repeatedly as long as a condition is True. Here's an example of a while loop that prints the numbers from 1 to 5: + +``` python +i = 1 +n = 5 + +# while loop from i = 1 to 5 +while i <= n: + print(i) + i = i + 1 +``` + +Output: +``` +1 +2 +3 +4 +5 +``` + +## Functions +Functions are reusable chunks of code with argument/parameters and return values. +Using the `def` keyword in Python, you can define a function. In your programme, functions can be used to encapsulate complex logic and can be called several times. +Functions can also be used to simplify code and make it easier to read. Here is an illustration of a function that adds two numbers: + +``` python +# function has two arguments num1 and num2 +def add_numbers(num1, num2): + sum = num1 + num2 + print('The sum is: ',sum) +``` + +``` python +# calling the function with arguments to add 5 and 2 +add_numbers(5, 2) + +# Output: The sum is: 9 +``` + +## Understanding Modules and Importing Libraries: +A module is a file in Python that contains definitions and statements. Modules let you arrange your code and reuse it across many apps. +The Standard Library, a sizable collection of Python modules, offers a wide range of capabilities, such as file I/O, regular expressions, and more. +Additional libraries can be installed using package managers like pip. +You must import a module or library using the import statement in order to use it in your programme. Here is an illustration of how to load the math module and calculate a number's square root using the sqrt() function: + +``` python +import math + +print(math.sqrt(16)) # 4.0 +``` + +## File I/O +File I/O is used to read and write data to and from files on disk. +The built-in Python function open() can be used to open a file, after which you can read from and write to it using methods like read() and write(). +To save system resources, you should always close the file after you are done with it. +An example of reading from a file and printing its content: + +``` python +f = open("90DaysOfDevOps.txt", "r") +print(f.read()) +f.close() +``` + +## Exception Handling: + +Exceptions are runtime errors that happen when your programme runs into unexpected circumstances, such dividing by zero or attempting to access a list element that doesn't exist. +Using a try/except block, you can manage exceptions in Python. The try block's code is run, and if an exception arises, the except block's code is run to handle the exception. + +``` python +try: + f = open("90DaysOfDevOps.txt") + try: + f.write("Python is great") + except: + print("Something went wrong when writing to the file") +``` + +## Conclusion + +That is it for today, I will see you tomorrow in Day 3 of Python!