Fundamentos de Python

Cartões · 60

Print to console

print('Hello, World!')

Variable assignment

x = 10 name = 'Alice'

Multiple assignment

a, b = 1, 2

Formatted string (f-string)

name = 'Bob' print(f'Hello, {name}!')

User input

user_name = input('Enter your name: ')

Type casting to integer

num = int('42')

Type casting to string

text = str(100)

Check variable type

print(type(42)) # <class 'int'>

Single-line comment

# This is a single line comment

Multi-line string or comment

text = '''This spans multiple lines'''

Arithmetic division vs floor division

print(7 / 2) # 3.5 print(7 // 2) # 3

Modulus operator

remainder = 10 % 3 # 1

Exponentiation

power = 2 ** 3 # 8

Conditional if-elif-else

if x > 0: print('pos') elif x < 0: print('neg') else: print('zero')

Ternary operator

status = 'adult' if age >= 18 else 'minor'

Logical operators (and, or, not)

if x > 0 and not is_closed: print('Open and positive')

While loop

i = 0 while i < 3: print(i) i += 1

For loop with range

for i in range(5): print(i) # 0 to 4

Loop with break

for n in range(10): if n == 5: break

Loop with continue

for n in range(5): if n == 2: continue print(n)

Defining a function

def greet(name): return f'Hi, {name}'

Function with default arguments

def power(base, exp=2): return base ** exp

Arbitrary positional arguments (*args)

def total(*nums): return sum(nums)

Arbitrary keyword arguments (**kwargs)

def show_info(**kwargs): print(kwargs)

Lambda function

square = lambda x: x ** 2 print(square(4)) # 16

Create a list

fruits = ['apple', 'banana', 'cherry']

Append item to list

items = [1, 2] items.append(3)

Insert item at specific index

items = ['a', 'c'] items.insert(1, 'b')

Remove item from list by value

items = ['a', 'b', 'c'] items.remove('b')

Pop item from list

items = [1, 2, 3] last = items.pop()

List slicing

nums = [0, 1, 2, 3, 4] print(nums[1:4]) # [1, 2, 3]

List comprehension

squares = [x**2 for x in range(5)]

List comprehension with filter

evens = [x for x in range(10) if x % 2 == 0]

Create a tuple

point = (10, 20)

Tuple unpacking

x, y = (10, 20)

Create a dictionary

user = {'name': 'Ana', 'age': 25}

Access dictionary with get

age = user.get('age', 0)

Iterate dictionary keys and values

for k, v in user.items(): print(k, v)

Dictionary comprehension

squares = {x: x**2 for x in range(3)}

Create a set

unique_ids = {1, 2, 2, 3} # {1, 2, 3}

Set union and intersection

a = {1, 2} b = {2, 3} print(a | b) # union print(a & b) # inter

String length

length = len('Python') # 6

String split and join

words = 'a,b,c'.split(',') joined = '-'.join(words)

String strip whitespace

clean = ' hello '.strip() # 'hello'

Check substring presence

if 'py' in 'python': print('Found!')

Try-except error handling

try: res = 10 / 0 except ZeroDivisionError: res = None

Try-except-finally block

try: f = open('file.txt') finally: print('Execution finished')

Raise an exception

if age < 0: raise ValueError('Age cannot be negative')

Read file with context manager

with open('data.txt', 'r') as f: content = f.read()

Write text to a file

with open('out.txt', 'w') as f: f.write('Hello file!')

Import a module

import math print(math.sqrt(16)) # 4.0

Import specific function from module

from random import randint val = randint(1, 6)

Define a class with __init__

class Dog: def __init__(self, name): self.name = name

Class method and self

class Cat: def speak(self): return 'Meow'

Class inheritance

class Animal: pass class Dog(Animal): pass

Enumerate a sequence

for index, value in enumerate(['a', 'b']): print(index, value)

Zip multiple iterables

names = ['a', 'b'] scores = [1, 2] combined = list(zip(names, scores))

Any and all built-in checks

has_true = any([False, True]) all_true = all([True, True])

Sorted function with key

words = ['banana', 'pie'] sorted_words = sorted(words, key=len)

Main guard boilerplate

if __name__ == '__main__': print('Executed directly')