Hi Dev Community 😊 👩💻👨💻
I'm posting here some codes to help you start you Python journey, I hope they can be useful for you.
English is my second language, I apologize if I have made anywhere writing mistakes 😅
- Basic Syntax
# Print "Hello, world!" to the console
print("Hello, world!")
# Declare and assign a variable
my_variable = 10
# Conditional statement
if my_variable > 5:
print("my_variable is greater than 5")
else:
print("my_variable is less than or equal to 5")
# Loop through a list
my_list = [1, 2, 3, 4, 5]
for item in my_list:
print(item)
# Define a function
def my_function(param1, param2):
return param1 + param2
# Call a function
result = my_function(2, 3)
print(result)
- Data types and structures
# Integer
my_int = 10
# Float
my_float = 3.14
# String
my_string = "Hello, world!"
# Boolean
my_bool = True
# List
my_list = [1, 2, 3, 4, 5]
# Tuple
my_tuple = (1, 2, 3)
# Set
my_set = {1, 2, 3}
# Dictionary
my_dict = {"name": "John", "age": 30, "city": "New York"}
-File handling
# Open a file
file = open("file.txt", "w")
# Write to a file
file.write("Hello, world!")
# Close a file
file.close()
# Open a file for reading
file = open("file.txt", "r")
# Read from a file
contents = file.read()
# Close a file
file.close()
-Libraries and modules
# Import a module
import math
# Use a function from a module
result = math.sqrt(16)
print(result)
# Import a specific function from a module
from random import randint
# Use the imported function
random_number = randint(1, 10)
print(random_number)
# Import a custom module
import my_module
# Use a function from the custom module
result = my_module.my_function(2, 3)
print(result)
-List Operations
# Create a list
my_list = [1, 2, 3, 4, 5]
# Append to a list
my_list.append(6) = ("new_element")
# Remove from a list
my_list.remove(3)
# Get the length of a list
length = len(my_list)
# Sort a list
my_list.sort()
# Reverse a list
my_list.reverse()
# Sort a list in alphabetic reserve order
my_list.sort(reverse="True")
# Extend the list with another list
my_list.extend(["element","element1"])
-List Comprehension
# Create a new list using list comprehension
my_list = [1, 2, 3, 4, 5]
new_list = [x * 2 for x in my_list]
print(new_list)
# Create a new list with condition using list comprehension
my_list = [1, 2, 3, 4, 5]
new_list = [x for x in my_list if x % 2 == 0]
print(new_list)
-Tuples Operations
# Creating a tuple
my_tuple = (1, 2, 3, 4, 5)
# Creating a single-element tuple (note the comma)
single_element_tuple = (42,)
# Creating an empty tuple
empty_tuple = ()
-Accessing elements in tuples
# Accessing elements by index
first_element = my_tuple[0]
last_element = my_tuple[-1]
# Slicing a tuple
subset_tuple = my_tuple[1:4]
# Tuple unpacking
a, b, c, d, e = my_tuple
-Iterating trough a tuple
for item in my_tuple:
print(item)
# Using enumerate to access both index and value
for index, value in enumerate(my_tuple):
print(f"Index {index}: {value}")
-Checking "membership"
# Checking if an element exists in a tuple
if 3 in my_tuple:
print("3 is in the tuple")
-Tuples immutability
Trying/attempting to modify a tuple will result in a error
my_tuple[0] = 10 # Raises a TypeError: 'tuple' object does not support item assignment
-Soo how to "add elements" to it? You can concatenate 2 tuples into 1
# Concatenating two tuples
tuple1 = (1, 2, 3)
tuple2 = (4, 5, 6)
concatenated_tuple = tuple1 + tuple2
# Repeating a tuple
repeated_tuple = (0,) * 3 # Creates (0, 0, 0)
-Dictionary Operations
# Create a dictionary
my_dict = {"name": "John", "age": 30, "city": "New York"}
# Access a value in a dictionary
name = my_dict["name"]
# Add a new key-value pair to a dictionary
my_dict["country"] = "USA"
# Remove a key-value pair from a dictionary
del my_dict["age"]
# Check if a key exists in a dictionary
if "name" in my_dict:
print("Name exists in the dictionary")
# Get the keys and values of a dictionary as lists
keys = list(my_dict.keys())
values = list(my_dict.values())
-Classes Operations
# Define a class
class Person:
def __init__(self, name, age):
self.name = name
self.age = age
def say_hello(self):
print(f"Hello, my name is {self.name} and I am {self.age} years old.")
# Create an object of a class
person1 = Person("John", 30)
# Call a method of an object
person1.say_hello()
-Sets operations
Sets are unordered,unique and mutable collections but they don't repeat elements, if you want to convert a list into a set and there are 2 elements repeated like: my_list={"computer","mouse","mouse-pad","keyboard","mouse-pad"}, when printing set(my_list) it only has mouse-pad 1 time because of the propriety of uniqueness (don't allow duplicate elements).
# Creating a set
my_set = {1, 2, 3}
# Adding elements to a set
my_set.add(4)
# Removing an element from a set
my_set.remove(2)
# Checking if an element is in a set
if 3 in my_set:
print("3 is in the set")
# Iterating through a set
for item in my_set:
print(item)
# Set operations
set1 = {1, 2, 3}
set2 = {3, 4, 5}
# Union of two sets
union_set = set1.union(set2)
# Intersection of two sets
intersection_set = set1.intersection(set2)
# Difference between two sets
difference_set = set1.difference(set2)
# Symmetric difference between two sets
symmetric_difference_set = set1.symmetric_difference(set2)
Stay tuned for part_2 🥰
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