Introduction To Programming with Python-1
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The document outlines a programming class focused on Python, covering key concepts such as variables, functions, algorithms, and flow control. It includes definitions and examples of fundamental programming constructs, including the creation of a simple calculator and a mini-project for a rock-paper-scissors game. Additionally, it discusses the differences between source code and object code, as well as the role of compilers in programming.
![Defining Functions
The statement return [expression] exits a function, optionally passing
back an expression to the caller. A return statement with no
arguments is the same as return None.
General Form of Return Statement:
return [expression]
Example:
def MyFunction():
“”“A function that returns a message”””
return “This is a function that returns a message”](https://image.slidesharecdn.com/introductiontoprogrammingwithpython-lecture1-140910085055-phpapp02/85/Introduction-To-Programming-with-Python-1-10-320.jpg)
![Conditional Execution
In order to write useful programs, we almost always need to check
some conditions and change the program accordingly. Conditional
Statements gives us this ability. The simplest form is if statement.
General Form:
if [expression1]:
body1
elif [expression2]:
body2
else:
bodyN](https://image.slidesharecdn.com/introductiontoprogrammingwithpython-lecture1-140910085055-phpapp02/85/Introduction-To-Programming-with-Python-1-17-320.jpg)
Introduction To Programming with Python-1
- 1. Introduction to Programming with Python – Class 1 SYED FARJAD ZIA ZAIDI
- 2. Class Objectives Class Objective Review variables, statements, expressions, functions, algorithms and technical terms. Understanding Flow Control. Write a simple program that performs addition, subtraction, multiplication and division using Functions.
- 3. Class Material •Chapter 1, 2, 3 - Python for Informatics: Exploring Information Reading Assignment •Rock, Paper, Scissors
- 4. Variables Definition: A named piece of memory that can store a value. Statement: A statement written in a programming language stores a value in a variable. Example: X = 5 Y = 1 Expression: A variable that has a value can be used in an expression. Example: X = X + 4 Y = X + 1
- 5. Rules for defining a Variable: Names must start with a letter or _. Names must contain only letters, digits, and _.
- 6. Questions?
- 7. Functions Definition: A function is a block of organized, reusable code that is used to perform some action. Defining a function: You can define a function in Python using the Keyword ‘def’. General Form of Function: def function_name(parameters): body Example: def MyFirstFunction(): print “This is my first function in Python Programming Language”
- 8. Defining Functions You can define functions to provide the required functionality. Here are simple rules to define a function in Python. Function blocks begin with the keyword ‘def’ followed by the function name and parentheses ‘( )’ . Example: def MyFirstFunction(): Any input parameters or arguments should be placed within these parentheses. You can also define parameters inside these parentheses. Example: def MySecondFunction(passedInput):
- 9. Defining Functions The first statement of a function can be an optional statement - the documentation string of the function or docstring. Example: def MyFirstFunction(): “””This is the 'docstring' which defines the function for other programmers to understand easily””” The code block within every function starts with a colon (:) and is indented.
- 10. Defining Functions The statement return [expression] exits a function, optionally passing back an expression to the caller. A return statement with no arguments is the same as return None. General Form of Return Statement: return [expression] Example: def MyFunction(): “”“A function that returns a message””” return “This is a function that returns a message”
- 11. Calling a function Function calls are expressions and the result can be stored in a variable. The general form of a function call: function_name(arguments) Example: MyFirstFunction() MySecondFunction(“Input Parameter”)
- 12. Questions?
- 13. Source Code vs Object Code Source Code Object Code Source Code is a text file version of a computer program or software that contains instructions that the computer follows to do something Object code, or sometimes an object module, is what a computer compiler produces Source code is written in a programming language which a human can read and change In a general sense object code is a sequence of statements or instructions in a computer language, usually a machine code language (i.e., 1's and 0's) Most source code is compiled when it is finished Object code is the resulting code after compiling source code
- 14. Compiler A compiler is a computer program (or set of programs) that transforms source code written in a programming language (the source language) into another computer language (the target language, often having a binary form known as object code). The most common reason for wanting to transform source code is to create an executable program.
- 15. Questions?
- 16. Flow Control of the Program Selection (If/Else) Repetition (Loops)
- 17. Conditional Execution In order to write useful programs, we almost always need to check some conditions and change the program accordingly. Conditional Statements gives us this ability. The simplest form is if statement. General Form: if [expression1]: body1 elif [expression2]: body2 else: bodyN
- 18. Python Comparison Operators Operator Description == Checks if the value of two operands are equal or not, if yes then condition becomes true. != Checks if the value of two operands are equal or not, if values are not equal then condition becomes true. < Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true. > Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true. >= Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true. <= Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true.
- 19. Python Logical Operators Operator Description and Called Logical AND operator. If both the operands are true then then condition becomes true. or Called Logical OR Operator. If any of the two operands are non zero then then condition becomes true. not Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true then Logical NOT operator will make false.
- 20. Questions?
- 21. Simple Calculator Definition: A calculator is a machine which allows people to do math operations more easily. For example, most calculators will add, subtract, multiply, and divide. Instructions for writing the Program: There should be 4 functions in your program: Add(number1, number2) Subtract(number1, number2) Multiply(number1, number2) Divide(number1, number2) The template for the program can be accessed here: http://www.codeskulptor.org/#user37_44o34rWsnC_18.py
- 22. Questions?
- 23. Rock Paper Scissors – 1st Mini- Project Rock-paper-scissors is a hand game that is played by two people. The players count to three in unison and simultaneously "throw” one of three hand signals that correspond to rock, paper or scissors. The winner is determined by the rules: Rock smashes scissors Scissors cuts paper Paper covers rock
- 24. Instruction In our first mini-project, we will build a Python function rps(name) that takes as input the string name, which is one of "rock", "paper", "scissors“. The function then simulates playing a round of rock-paper-scissors by calling a helper function gen_random_num() that generate own random choice from these alternatives and then determining the winner using simple if / else statements. The mini-project template is here: http://www.codeskulptor.org/#user37_HJPdXx35jy_0.py
- 25. Example runs Player chooses rock Computer chooses scissors Player wins! Player chooses paper Computer chooses scissors Computer wins! Player chooses scissors Computer chooses paper Player wins!
- 26. Questions?