Sample code for the article on first steps with Python (#699)

* Sample code for the article on first steps with Python

* Fix linter issues

* More fixes

* Final QA

---------

Co-authored-by: brendaweles <[email protected]>
Co-authored-by: Bartosz Zaczyński <[email protected]>

Author: 3 people

python-first-steps/README.md

@@ -0,0 +1,3 @@
+# How to Use Python: Your First Steps
+
+This folder provides the code examples for the Real Python tutorial [How to Use Python: Your First Steps](https://realpython.com/python-first-steps/).

python-first-steps/boolean.py

@@ -0,0 +1,15 @@
+# Comparisons
+print(2 < 5)
+print(4 > 10)
+print(4 <= 3)
+print(3 >= 3)
+print(5 == 6)
+print(6 != 9)
+
+# The bool() function
+print(bool(0))
+print(bool(1))
+print(bool(""))
+print(bool("a"))
+print(bool([]))
+print(bool([1, 2, 3]))

python-first-steps/bytes.py

@@ -0,0 +1,23 @@
+# Literal syntax (ASCII only)
+print(b"Hello")
+# From an iterable of integers (0 to 255)
+print(bytes([72, 101, 108, 108, 111]))
+# By encoding a string
+print("café".encode("utf-8"))
+
+data = b"caf\xc3\xa9"
+data.decode("utf-8")
+print(data)
+
+packet = b"ABCDEF"
+print(len(packet))
+print(packet[0])
+print(packet[1:4])
+
+buffer = bytearray(b"ABC")
+buffer[0] = 97
+print(buffer)
+print(bytes(buffer))
+
+print(b"Hello".hex())
+print(bytes.fromhex("48656c6c6f"))

python-first-steps/classes.py

@@ -0,0 +1,12 @@
+class Dog:
+    def __init__(self, name, age):
+        self.name = name
+        self.age = age
+
+    def bark(self):
+        return "Woof! Woof!"
+
+
+fido = Dog("Fido", 3)
+print(fido.name, fido.age)
+print(fido.bark())

python-first-steps/comments.py

@@ -0,0 +1,6 @@
+# This is a comment on its own line
+
+greeting = "Hello, World!"  # This is an inline comment
+
+# This is a long comment that requires
+# two lines to be complete.

python-first-steps/conditionals.py

@@ -0,0 +1,18 @@
+age = 21
+
+if age >= 18:
+    print("You're a legal adult")
+
+age = 16
+
+if age >= 18:
+    print("You're a legal adult")
+else:
+    print("You're NOT an adult")
+
+age = 18
+
+if age > 18:
+    print("You're over 18 years old")
+elif age == 18:
+    print("You're exactly 18 years old")

python-first-steps/dictionaries.py

@@ -0,0 +1,13 @@
+john = {"name": "John Doe", "age": 25, "job": "Python Developer"}
+print(john)
+jane = dict(name="Jane Doe", age=24, job="Web Developer")
+print(jane)
+print(john["name"])
+print(john["age"])
+
+# Retrieve all the keys
+print(john.keys())
+# Retrieve all the values
+print(john.values())
+# Retrieve all the key-value pairs
+print(john.items())

python-first-steps/for_loops.py

@@ -0,0 +1,16 @@
+for i in (1, 2, 3, 4, 5):
+    print(i)
+else:
+    print("The loop wasn't interrupted")
+
+for i in (1, 2, 3, 4, 5):
+    if i == 3:
+        print("Number found:", i)
+        break
+else:
+    print("Number not found")
+
+for i in (1, 2, 3, 4, 5):
+    if i == 3:
+        continue
+    print(i)

python-first-steps/hello.py

@@ -0,0 +1 @@
+print("Hello, World!")

python-first-steps/imports.py

@@ -0,0 +1,9 @@
+import math  # Module import
+from math import pi as PI  # Import with alias
+from math import sqrt  # Function import
+
+print(math.sqrt(16))
+
+print(sqrt(25))
+
+print(PI)