Python programming workshop
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The document outlines a Python programming workshop covering fundamental topics such as expressions, operators, control flows, and functions. It details the Python interpreter, input/output strategies, data types, and object-oriented programming concepts, including classes and methods. Additionally, it provides practical examples of programming constructs like loops, conditional statements, and list comprehensions.
![List
12
list1 = list() # Create an empty list
list2 = list([2, 3, 4]) # Create a list with elements 2, 3, 4
list3 = list(["red", "green", "blue"]) # Create a list with strings
list4 = list(range(3, 6)) # Create a list with elements 3, 4, 5
list5 = list("abcd") # Create a list with characters a, b, c
list1 = [] # Same as list()
list2 = [2, 3, 4] # Same as list([2, 3, 4])
list3 = ["red", "green"] # Same as list(["red", "green"])
append(x: object): None
insert(index: int, x: object): None
remove(x: object): None
index(x: object): int
count(x: object): int
sort(): None
reverse(): None
extend(l: list): None
pop([i]): object](https://image.slidesharecdn.com/pythonprogrammingworkshop-170817032308/85/Python-programming-workshop-12-320.jpg)
![List Is a Sequence Type
13
Operation Description
x in s True if element x is in sequence s
x not in s True if element x is not in sequence s
s1 + s2 Concatenates two sequences s1 and s2
s * n, n * s n copies of sequence s concatenated
s[i] ith element in sequence s
s[i : j] Slice of sequence s from index i to j - 1
len(s) Length of sequence s, i.e., the number of elements in s
min(s) Smallest element in sequence s
max(s) Largest element in sequence s
sum(s) Sum of all numbers in sequence s
for loop Traverses elements from left to right in a for loop
<, <=, >, >=, ==, != Compares two sequences](https://image.slidesharecdn.com/pythonprogrammingworkshop-170817032308/85/Python-programming-workshop-13-320.jpg)
![Reading Input from Text Files
22
continent = input('Enter the name of a continent : ')
continent = continent.title()
if continent != 'Antarctica':
infile = open('UN.txt', 'r')
for line in infile:
data = line.split(',')
if data[1] == continent:
print(data[0])
else:
print('There are not countries in Antarctica.')
infile = open(‘Filename’, ‘r’)](https://image.slidesharecdn.com/pythonprogrammingworkshop-170817032308/85/Python-programming-workshop-22-320.jpg)
![List Comprehension
23
list1 = [x for x in range(5)]
[0, 1, 2, 3, 4]
line = input('Enter series of numbers : ')
text_numbers = line.split(' ')
numbers = [eval(num) for num in text_numbers]](https://image.slidesharecdn.com/pythonprogrammingworkshop-170817032308/85/Python-programming-workshop-23-320.jpg)
Python programming workshop
- 2. Topics Expressions, operators, precedence, control flows, functions Input/output List Classes and Objects 2
- 3. The Python Interpreter Python is an interpreted language Commands are executed through the Python interpreter A programmer defines a series of commands in advance and saves those commands in a text file known as source code or a script. For Python, source code is conventionally stored in a file named with the .py suffix (e.g., demo.py) 3
- 4. Writing a Simple Program Algorithm for calculating the area of a square Obtain the width from the user Computer the area by applying the following formula 𝒂𝒓𝒆𝒂 = 𝒘𝒊𝒅𝒕𝒉 ∗ 𝒘𝒊𝒅𝒕𝒉 Display the result 4
- 5. Reading Input from the Console Use the input function to obtain a string variable = input(‘Enter width : ’) Use the eval function to evaluate expression variable = eval(string_variable) Combination width = eval(input(‘Enter width : ’)) 5
- 6. Calculating Square Area width = eval(input('Enter width : ')) area = width * width print('Area is ', area) 6
- 7. Identifiers Identifiers in Python are case-sensitive, so temperature and Temperature are distinct names. Identifiers can be composed of almost any combination of letters, numerals, and underscore characters. An identifier cannot begin with a numeral and that there are 33 specially reserved words that cannot be used as identifiers: 7
- 8. Types Python is a dynamically typed language, as there is no advance declaration associating an identifier with a particular data type. An identifier can be associated with any type of object, and it can later be reassigned to another object of the same (or different) type. Although an identifier has no declared type, the object to which it refers has a definite type. In our first example, the characters 98.6 are recognized as a floating-point literal, and thus the identifier temperature is associated with an instance of the float class having that value. 8
- 9. Numerical Data Types ad Numeric Operators integer: e.g., 3, 4 float: e.g., 3.0, 4.0 Name Meaning Example Result + Addition 34 + 1 35 - Subtraction 34.0 – 0.1 33.9 * Multiplication 300 * 30 9000 / Float Division 1 / 2 0.5 // Integer Division 1 // 2 0 ** Exponentiation 4 ** 0.5 2.0 % Remainder 20 % 3 2 9
- 10. Boolean Data Types Often in a program you need to compare two values, such as whether i is greater than j There are six comparison operators (also known as relational operators) that can be used to compare two values The result of the comparison is a Boolean value: true or false Operator Name < less than <= less than or equal to > greater than >= greater than or equal to == equal to != not equal to 10
- 11. String Sequence of characters that is treated as a single item Written as a sequence of characters surrounded by either single quotes (') or double quotes (") Position or index of a character in a string Identified with one of the numbers 0, 1, 2, 3, . . . . 11
- 12. List 12 list1 = list() # Create an empty list list2 = list([2, 3, 4]) # Create a list with elements 2, 3, 4 list3 = list(["red", "green", "blue"]) # Create a list with strings list4 = list(range(3, 6)) # Create a list with elements 3, 4, 5 list5 = list("abcd") # Create a list with characters a, b, c list1 = [] # Same as list() list2 = [2, 3, 4] # Same as list([2, 3, 4]) list3 = ["red", "green"] # Same as list(["red", "green"]) append(x: object): None insert(index: int, x: object): None remove(x: object): None index(x: object): int count(x: object): int sort(): None reverse(): None extend(l: list): None pop([i]): object
- 13. List Is a Sequence Type 13 Operation Description x in s True if element x is in sequence s x not in s True if element x is not in sequence s s1 + s2 Concatenates two sequences s1 and s2 s * n, n * s n copies of sequence s concatenated s[i] ith element in sequence s s[i : j] Slice of sequence s from index i to j - 1 len(s) Length of sequence s, i.e., the number of elements in s min(s) Smallest element in sequence s max(s) Largest element in sequence s sum(s) Sum of all numbers in sequence s for loop Traverses elements from left to right in a for loop <, <=, >, >=, ==, != Compares two sequences
- 14. if Statement 14 if width > 0: area = width * width if Boolean-expression: statement(s)
- 15. if-else Statement 15 if width > 0: area = width * width else: print(‘width must be positive’) if Boolean-expression: statement(s) for the true case else: statement(s) for the false case
- 16. Multiple Alternative for if Statements 16 if score >= 90.0: grade = 'A' elif score >= 80.0: grade = 'B' elif score >= 70.0: grade = 'C' elif score >= 60.0: grade = 'D' else: grade = 'F' if score >= 90.0: grade = 'A' else: if score >= 80.0: grade = 'B' else: if score >= 70.0: grade = 'C' else: if score >= 60.0: grade = 'D' else: grade = 'F'
- 17. Logical Operators 17 Operator Description not Logical negation and Logical conjunction or Logical disjunction (year % 4 == 0 and year % 100 != 0) or year % 400 == 0) A year is a leap year if it is divisible by 4 but not by 100, or it is divisible by 400.
- 18. Conditional Operator 18 y = 1 if x > 0 else -1if x > 0: y = 1 else: y = -1 if num % 2 == 0: print(str(num) + “is even”) else: print(str(num) + “is odd”); print("number is even" if (number % 2 == 0) else "number is odd")
- 19. Operator Precedence +, - unary ** not *, /, //, % +, - <, <=, >, >= ==, != and or =, +=, -=, *=, /=, //=, %= (Assignment operator) 19
- 20. Loops 20 for i in range(1, 6): print (i) num = 1 while num <= 5: print(num) num += 1 while conditions: indented block of statements for var in sequence: indented block of statements
- 21. Functions Functions can be used to define reusable code and organize and simplify code 21 def sum_range(a, b): result = 0 for i in range(a, b+1): result += i return result def main(): print('Sum from 1 to 10 is ', sum_range(1, 10)); print('Sum from 50 to 100 is ', sum_range(50, 100)); main() def function_name(list of parameters): # Function body
- 22. Reading Input from Text Files 22 continent = input('Enter the name of a continent : ') continent = continent.title() if continent != 'Antarctica': infile = open('UN.txt', 'r') for line in infile: data = line.split(',') if data[1] == continent: print(data[0]) else: print('There are not countries in Antarctica.') infile = open(‘Filename’, ‘r’)
- 23. List Comprehension 23 list1 = [x for x in range(5)] [0, 1, 2, 3, 4] line = input('Enter series of numbers : ') text_numbers = line.split(' ') numbers = [eval(num) for num in text_numbers]
- 24. Objects and Classes Object-oriented programming enables you to develop large-scale software and GUIs effectively. 24 class Rectangle: def __init__(self, width = 1, height = 2): self._width = width self._height = height def area(self): return self._width * self._height def perimeter(self): return 2 * (self._width * self._height) def main(): r1 = Rectangle(10, 20) print('The area of the rectangle is : ', r1.area()) print('The perimeter of the rectangle is : ', r1.perimeter()) main() class ClassName: initializer methods