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![Nested for Loop for [first iterating variable] in [outer loop]: [code line 1] [code line 2] for [second iterating variable] in [nested loop]: [code line 1] 1st level loop or outer loop Nested loop 1st indentation 2nd indentation Dr. Poonam Panwar, Associate Professor, CUIET 97](https://image.slidesharecdn.com/1-221002143059-d435c944/75/1-PGA2-0-Python-Programming-Intro-to-Python-pptx-97-2048.jpg)
1. PGA2.0-Python Programming-Intro to Python.pptx
- 1. Python Programming Introduction to Python 02-10-2022Dr. Poonam Panwar, Associate Professor, CUIET 1
- 2. Agenda In this session,you will learn about: • Introduction to Python • Variables • Functions • Python Operators • Python Flow Controls • Conditional Statements • Loops
- 3. Introduction to Python Dr.Poonam Panwar, Associate Professor, CUIET 3
- 4. Some Common Languagesin use Dr. Poonam Panwar, Associate Professor, CUIET 4
- 5. Languages History Dr. PoonamPanwar, Associate Professor, CUIET 5
- 6. History of Python •First public release in 1991 • Open source from beginning • Managed by Python Software Foundation Invented in December 1989 Guido Van Rossum Dr. Poonam Panwar, Associate Professor, CUIET 6
- 7. Python Python drew inspirationfrom other programming languages: Python is powerful... and fast; plays well with others; runs everywhere; is friendly & easy to learn; is Open. Python is an interpreted language, do not need to be compiled to run. Python is a high-level language, which means a programmer can focus on what to do instead of how to do it. Writing programs in Python takes less time than in another language. Dr. Poonam Panwar, Associate Professor, CUIET 7
- 8. Python Used For Dr.Poonam Panwar, Associate Professor, CUIET 8
- 9. Compiling and Interpreting Manylanguages are required to compile the program into a form (ByteCode) that the machine understands. Python is instead directly interpreted into machine instructions. compile execute output source code Hello.java byte code Hello.class interpret output source code Hello.py Dr. Poonam Panwar, Associate Professor, CUIET 9
- 10. Development Environment Terminal / Shellbased Three most common options: iPython notebook IDLE (Spyder IDE) Dr. Poonam Panwar, Associate Professor, CUIET 10
- 11. Anaconda Dr. Poonam Panwar,Associate Professor, CUIET 11
- 12. Anaconda Navigator Dr. PoonamPanwar, Associate Professor, CUIET 12
- 13. Jupyter IDE Click hereto change the name of the notebook Write your code here Menu bar Running Python Kernel Execute the code using Run button or shift+enter
- 14. Jupyter IDE Dr. PoonamPanwar, Associate Professor, CUIET 14
- 15. Spyder IDE Dr. PoonamPanwar, Associate Professor, CUIET 15
- 16. A Python CodeSample Assignment uses = and comparison uses == For numbers +-*/% are as expected Logical operators are words (and, or, not) The basic printing command is print Start comments with #: the rest of line is ignored Dr. Poonam Panwar, Associate Professor, CUIET 16
- 17. Variables Dr. Poonam Panwar,Associate Professor, CUIET 17
- 18. Variables Variables are reservedmemory that store data Unlike languages like C, C++ and Java, Python has no command for declaring variable = operator is used to assign a value to a variable
- 19. We would onlyreceive the second assigned value as the output since that was the most recent assignment Reassigning Variables
- 20. Reassigning Variables You canconnect a different value with a previously assigned variable very easily through simple reassignment
- 21. Multiple Variable Assignment Withsame value
- 22. Multiple Variable Assignment Withdifferent values
- 23. Data Types String NumericBoolean None Collection Integer Float List Tuple Dictionary Set Data Types in Python
- 24. Data Types String NumericBoolean None Collection Integer Float List Tuple Dictionary Set We will learn the following data types today
- 25. String variables arevariables that hold zero or more characters such as letters, numbers, spaces, commas and many more Creating String Variables Use type(variable_name) to check the data type of variable declared
- 26. Creating Numeric Variables Asseen earlier, there are two types of numeric data types: Integer Float A numeric variable is one that may take on any value within a finite or infinite interval
- 27. Creating Boolean Variables Booleanvariables are variables that can have only two possible values: True False
- 28. Data Type Conversion TypeConversion Implicit Conversion Explicit Conversion Python supports conversion of one data type to another
- 29. Data Type Conversion TypeConversion Implicit Conversion Explicit Conversion Arithmetic Operation Casting Operation Implicit Conversion: Conversion done by Python interpreter without programmer’s intervention Explicit Conversion: Conversion that is user-defined that forces an expression to be of specific data type
- 30. Implicit Conversion In ImplicitConversion, the conversion is done by Python interpreter without programmer’s intervention
- 31. Explicit Conversion In ExplicitConversion, conversion that is user-defined forces an expression to be of specific data type Example
- 32. Explicit Conversion Explicit datatype conversion using float() function
- 33. Type Casting Type Casting float()bool() str() int()
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- 35. Functions Dr. Poonam Panwar,Associate Professor, CUIET 35
- 36. What are Functions? Afunction is a block of reusable code that runs when called Function name: sum() Input parameters Return value of the function • A function has a name. You call the function by its name • A function can take input(s), known as input parameters • A function can return data as a result
- 37. What are Functions? Thereare three types of functions: Built-in Functions User-defined Functions Lambda Functions Some of the built-in functions are: print() - to print the output input() - to take input from user the type casting functions like int(), float(), str(), bool(), etc. We will study the user-defined functions and lambda functions in detail in our upcoming sessions
- 38. The print() functionprints the specified message to the screen The message can be a string, or any other object The object will be converted into a string before written to the screen The print() in Python strings separated by a comma within a print() function get concatenated. strings separated by a comma within a print() function get concatenated.
- 39. The print() inPython The sep is an optional parameter. When output is printed, each word is separated by comma and space character print(‘n’) gives a new blank line The backslash “” is a special character that represents whitespaces. For example ‘t’ is a tab and ‘n’ is a new line.
- 40. Invalid use ofopening and closing quotes is not allowed.
- 41. Concatenation using print() Use+ operator to concatenate two strings
- 42. Adding numbers tostrings does not make any sense. Please consider explicit conversion to convert the number to string first, in order to join them together. You cannot concatenate string & number.
- 43. Concatenation with TypeCasting Explicit conversion of a number to string with str() function. We learn more such type conversions in our upcoming sessions
- 44. Python Operators Dr. PoonamPanwar, Associate Professor, CUIET 44
- 45. Python Operators The PythonOperators are: Arithmetic Operators Relational Operators Logical Operators Membership Operators Bitwise Operators Assignment Operators The Python Operators are:
- 46. Python Operators The mostcommon Arithmetic Operators are: Addition Subtraction Multiplication Division Modulus Floor Division exponentiation + - * / % // **
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- 48. Arithmetic Operators Addition Note that22 is a string Here two strings are getting concatenated
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- 50. Arithmetic Operators Subtraction When twostrings are added, the + (addition) operator basically concatenates the two strings. Subtracting two strings does not make any sense.
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- 62. Relational operators areused to compare values and take certain decisions based on the outcome Relational Operators Following are some of the relational operators: Operators Meaning < Is less than <= Is less than & equal to > Is greater than >= Is greater than & equal to == Is equal to != Is not equal to
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- 64. Logical operators inPython allow a program to make a decision based on multiple conditions Each operand is considered a condition that can be evaluated to a true or false value Logical Operators Returns True if both the operands are true AND Returns True if either of the operands are True OR Returns true if the operand is false NOT
- 65. Logical Operators AND If boththe operands are true then it returns true
- 66. Logical Operators OR If oneof the operands are true then it returns true
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- 68. Membership Operators Membership operatorschecks whether a value is a member of a sequence. The sequence may be a list, a string, a tuple, or a dictionary in • The ‘in’ operator is used to check if a value exists in any sequence object or not not in • A ‘not in’ works in an opposite way to an ‘in’ operator. A ‘not in’ evaluates to True if a value is not found in the specified sequence object. Else it returns a False.
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- 71. Python Bitwise Operatorstake one to two operands, and operates on it/them bit by bit, instead of whole Some Bitwise Operators & (Bitwise and) • The binary and (&) takes two values and performs an AND-ing on each pair of bits. | (Bitwise or) • Compared to &, this one returns 1 even if one of the two corresponding bits from the two operands is 1.
- 72. Truth Tables | (Bitwiseor) & (Bitwise and) 02-10-2022 Dr. Poonam Panwar, Associate Professor, CUIET 72
- 73. Some Bitwise Operators |operator & operator Example (10 % 2 == 0) & (10 % 3 == 0) (10 % 2 == 0) | (10 % 3 == 0) Implies True & False. This results in False. Implies True | False. This results in True. 02-10-2022 Dr. Poonam Panwar, Associate Professor, CUIET 73
- 74. The assignment operatorsare used to store data into a variable More Assignment Operators
- 75. Python Flow Controls Dr.Poonam Panwar, Associate Professor, CUIET 75
- 76. Python Flow Control Anyprogram has a flow and the flow is the order in which the program’s code executes The control flow of a Python program is controlled by: Conditional Statements Loops Function Calls We cover the basics of conditional statements and loops in today’s session 02-10-2022 Dr. Poonam Panwar, Associate Professor, CUIET 76
- 77. Conditional Statements Dr. PoonamPanwar, Associate Professor, CUIET 77
- 78. ● The ifstatement is used in Python for decision making ● It is written by using the if keyword ● The if keyword is followed by condition later followed by indented block of code which will be executed only if the condition is true Syntax: if (condition): statement(s) The if-statement Dr. Poonam Panwar, Associate Professor, CUIET 78
- 79. The if-statement Example Dr. PoonamPanwar, Associate Professor, CUIET 79
- 80. ● The ‘if..else’statement evaluates a test expression and will execute: o the indented if block of code if the condition is True o the indented else block of code if the condition in the if statement is False The if-else statement Syntax: if (condition): Body of if else: Body of else Dr. Poonam Panwar, Associate Professor, CUIET 80
- 81. The if-else statement Example Dr.Poonam Panwar, Associate Professor, CUIET 81
- 82. Elif statement isused to control multiple conditions only if the given if condition is false The if elif else statement Syntax: if (condition1): Body of if elif (condition2): Body of elif elif (condition3): Body of elif . . . else: Body of else Dr. Poonam Panwar, Associate Professor, CUIET 82
- 83. The if elifelse statement Example Dr. Poonam Panwar, Associate Professor, CUIET 83
- 84. ● Nesting meansusing an if statement within another if statement ● If the first ‘if’ condition is satisfied then the program executes the commands within that ‘if’ Nested if-else statement Syntax: if (condition): statement(s) if (condition): statement(s) else: statement(s) else: statement(s) Dr. Poonam Panwar, Associate Professor, CUIET 84
- 85. Example Nested if-else statement Dr.Poonam Panwar, Associate Professor, CUIET 85
- 86. Example Nested if statement Dr.Poonam Panwar, Associate Professor, CUIET 86
- 87. Loops Dr. Poonam Panwar,Associate Professor, CUIET 87
- 88. ● Loops areused to execute of a specific block of code repetitively ● The ‘while loop’ in Python is used to iterate over a block of code as long as the test expression holds true ● This loop is used when the number of times to iterate is not known to us beforehand While loop Syntax: while (condition): Body of while Dr. Poonam Panwar, Associate Professor, CUIET 88
- 89. Example While loop Dr. PoonamPanwar, Associate Professor, CUIET 89
- 90. ● The ‘forloop’ in Python is used to iterate over the items of a sequence object like list, tuple, string and other iterable objects ● The iteration continues until we reach the last item in the sequence object The for Loop Syntax: for i in sequence: Body of for Dr. Poonam Panwar, Associate Professor, CUIET 90
- 91. Example The for Loop Iterationis a general term for taking each item from a sequence one after another Dr. Poonam Panwar, Associate Professor, CUIET 91
- 92. Loops in Pythonallows us to repeat tasks Getting out of a Loop Exit a loop completely when a certain condition is triggered But at times, you may want to: Skip part of a loop and start next execution Dr. Poonam Panwar, Associate Professor, CUIET 92
- 93. • The ‘break’statement ends the loop and resumes execution at the next statement • The break statement can be used in both ‘while’ loop and ‘for’ loop • It is always used with conditional statements Getting out with Break Statement Dr. Poonam Panwar, Associate Professor, CUIET 93
- 94. Getting out withBreak Statement Example Dr. Poonam Panwar, Associate Professor, CUIET 94
- 95. • The ‘continue’statement in Python ignores all the remaining statements in the iteration of the current loop and moves the control back to the beginning of the loop • The continue statement can be used in both ‘while’ loop and the ‘for’ loop • Like break, continue is also always used with conditional statements Skip Loop Step with Continue Statement Dr. Poonam Panwar, Associate Professor, CUIET 95
- 96. Skip Loop Stepwith Continue Statement Example Dr. Poonam Panwar, Associate Professor, CUIET 96
- 97. Nested for Loop for[first iterating variable] in [outer loop]: [code line 1] [code line 2] for [second iterating variable] in [nested loop]: [code line 1] 1st level loop or outer loop Nested loop 1st indentation 2nd indentation Dr. Poonam Panwar, Associate Professor, CUIET 97
- 98. Nested for Loop Outerloop Inner loop Dr. Poonam Panwar, Associate Professor, CUIET 98
- 99. Thank you Dr. PoonamPanwar, Associate Professor, CUIET 99