B.Sc Computer: Programming Concepts

• The exam was for B.Sc 3rd semester students
• The subject was Computer
• The paper title was "Programming Computer"
• The exam was in December 2021
• The date of the exam was 23/8/2022
• The paper code was GCS-005

Relational Operators

• Used for relational operations.

Lower() Function

• Refers to the lower function.

Interpreted Languages

• The code is executed line by line.
• The Hello
• The creator of Python is Guidovan Rossum.
• Functions: print().
• The operation of getting the remainder of a division problem.
• IDE stands for Integrated Development Learning Environment.
• Functions: Math.

Assigning values to names

• A statement that assigns a value to a name.
• The variable name is is to the left of equals sign (=), the assignment operator.
• To the right of the assignment operator is an expression.
• The expression is evaluated by the Python interpreter then assigned to the name.
• The keyword "del" erases objects
• "del" keyword can also be used to delete variables, lists, or parts of a list
• Everything in Python is an object

Debugging

• Debugging identifies, removes existing and potential errors in a software code, preventing unexpected behavior or crashes.

Decision Table

• A scheduled rule logic entry in table format.
• Conditions are represented on the row and column headings.
• Actions are represented as the intersection points of the condition cases in the table.

Addition Operator in Python (+)

• Used to add two values.

Subtraction Operator in Python (-)

• Used to subtract the second value from the first value.

Multiplication Operator in Python (*)

• Used to find the product of two values.

Division Operator in Python (/)

• Used to find the quotient when the first operand as divided by the second operand.

Modulus Operator in Python (%)

• Used to find the remainder where the first operand is divided by the second operand.

Features of Python

• Easy to learn and understand.
• Cross-platform programming language, usable with operating systems like Windows and Linus
• Interpreted language which executes code line by line.
• Object-oriented, procedural, and functional programming language.
• High-level programming language.
• Large global community.
• Large ecosystem of libraries, frameworks, and tools.

Variables

• A named place in memory that holds any type of data which the program can assign and modify.
• In Python there is no need to declare a variable explicitly by specifying whether the variable is an integer, float, or any other type.
• Variable names are case-sensitive.
• Python keywords are not allowed as a variable name.
• Variables should not start with a number.
• Variable names can consist of any number of letters, underscores, or digits.
• No white space is allowed within the variable name.

"if" Condition

• The syntax of the "if" statement is given by:
• "if" Boolean - expression: Statement 1 else: Statement 2
• The if statement evaluates the "Boolean-expression."
• If the condition is true, Statement 1 of the if statement is executed.
• Otherwise, the else statement executes if the first condition is false.

Break Statement

• A loop control statement that terminates the loop.
• once its encountered.
• The loop interaction stops, and control returns immediately to the first statement.
• Syntax: Break ;
• Example provided in the text for illustrating the use of Break statement

Global Variables

• Global variables are declared outside all the function blocks.
• The scope of variables remains throughout the program.
• Any changes affect the entire program wherever it is used.
• Global variables exist in the program for the entire runtime of when the program executed.
• If the global variable is not initialized, it takes it.

Local Variables

• Local variable are declared within a function block.
• The scope is limited and remains within the function only in which they are declared.
• Any changes in the local variable do not offset other function of the Program.
• A local variable is created when the function is created.
• Once the execution is finished, the variable is destroyed.
• If the local variable is not initialized, it takes it.

Python Math Functions

• math.acos() returns are cosine of a number
• math.acosh() returns inverse hyperbolic Cosine of a number
• math.asin() Return arc sine of a number
• math.asinh() Return inverse hyperbolic sine of a number
• math.atan() return arc tangent of the number in radian
• math.atan2() return arc tangent of y/x in radians.

Dictionaries

• Python's implementation of a data structure.
• Dictionaries are generally known as an associate way.
• A dictionary consists of a collection of key-value pairs.
• Each key-value pair maps the key to its associated value.
• A dictionary is a collection which is ordered changeable and does not allow duplicates
• Written with curly brackets and have keys and values.
• Dictionary items are presented in key: valued pairs and can be referred to by using key names.
• It means that the dictionary item have defined order, and that order will not change.
• Unordered means that the items does not haved a defined ordered and cannot refer to at item, therefore you cannot use using an index
• You cannot have two items with the same key
• Dictionaries are changeable, which means we change, add or remove items after creating the dictionary.

Dictionary Length

• To determine how many items a dictionary has, use the len() function.

Functions

• Defined by the users to perform specific tasks, are user-defined functions.
• Written by the users using the syntax: def function_name(): Statement
• We can pass parameters when defining a function.

Default Arguments

• A parameter that assumes a default value if a value is not provided in the function call for that argument.

Keyword Arguments

• Allows the caller to to specify argument names with values so that the caller does not need to remember the order of the parameters

Variable Length Arguments

• The special syntax *args in a function definition in Python is used to pass a variable number of arrangements to a function, in order pass a non-keyword, variable length argument
• The spectal syntax **kwargs in a function definition is used to parsed *keywords, variable - length argument
• Pass by reference or pass by value:

By Reference

• In pass by reference, teh address of the variable is directly passed as the and then the operation is done on the value stored at these address

By Value

• In pass by value, the value of the variable is directly passed as the value to

While Loops

• Used to repeat a section of code an unknown number to times until a specific condition is met.
• For example, to know how many times a given number can divide by to before it is less than or equal to one
• For a given symbolic variable "NUMBER" which represents any number in the world, how many times it is not known a priori.
• We could use a while loop to determine that answer.
• A recommended "pseudocode" for such an algorithm to keep dividing if is bigger by 2 or more keep a count of how many divisions there are.

Python Comments

• Can be used to explain python code

Operator Precedence

• Specifies how "tightly" binds less expressins together"
• For example, in the expression 1 +4*3, then answer is 13, the multiplication has is has a higher precedence than addition
• Parenthesis forces operator precedence (1+5)*3 evaluates to 18
• When operators have equal precedence, associativity of the operator determines the order of evalution
• Left associative example, 14-2-3 grouped as (14-2)-3 and evaluates to 9
• Non-associative operands cannot be neach to each other, for example 4 < 2 > 1 is illegal

Lecture notes for B.Sc 3rd semester computer students covering relational operators, lower() function, interpreted languages and assigning values to names, including the use of the 'del' keyword. It also mentions Python's creator Guido van Rossum and commonly used functions.