Tips & tricks in Python 3

tipc_and_tricks.py

"""
A collection of useful tips when working with Python 3
"""

import json
#  from collections import Hashable
from random import choice, randrange
# Check if sth is "hashable" cause Sets only store unique and hashable items
# Whereas Lists can store anything
#  print("Is empty object {} hashable? -> {0:b} ")
#  print(isinstance({}, Hashable))

primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41,
          43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]

# Iterate over list with index and value
for idx, val in enumerate(primes):
    print("At index {idx} is {prime}".format(idx=idx, prime=val))

print("\n\n---\n\n")

# Randomly select element from the list
alphabet = ["a", "b", "c", "d", "e", "f",
            "g", "h", "l", "m", "n", "o", "p", "q"]
print("The randomly chosen letter is \"{0:s}\"".format(choice(alphabet)))

# Using ranrange to select random index
randIndex = randrange(0, len(alphabet))
print("The randomly chosen letter is \"{0:s}\"".format(alphabet[randIndex]))

print("\n\n---\n\n")

# How to transform Lists into other data structures
# List of strings
list_of_strings = ["Hey", " ", "there", "!"]
welcome_message = "".join(list_of_strings)
print(welcome_message)

# List of integers
list_of_integers = [1, 2, 3]
print("-".join(str(n) for n in list_of_integers))

print("\n\n---\n\n")

# List to a Tuple - Tuples are immutable!
alphabet_tuple = tuple(alphabet)
print(alphabet_tuple)

print("\n\n---\n\n")

# List to a Set - Set can contain only unique, hashable items and there is no order
my_set = set(["a", "b", "b", "c", "d", "d"])
print(my_set)
print("is char \"a\" in set? {0:b}".format("a" in my_set))
print("is char \"f\" in set? {0:b}".format("f" in my_set))

print("\n\n---\n\n")

# List(s) to a Dictionary
chars = ["a", "b", "c"]
foos = ["foo", "bar", "baz"]
foo_dict = dict(zip(chars, foos))
print(foo_dict)  # {'a': 'foo', 'b': 'bar', 'c': 'baz'}

print("\n\n---\n\n")

# Working with JSON
# Writing to .json file
jedi = [
    {"name": "Obi-Wan Kenobi", "birth_year": "57BBY", "gender": "male"},
    {"name": "Luke Skywalker", "birth_year": "19BBY", "gender": "male"}
]
with open("jedi.json", "w") as write_file:
    json.dump(jedi, write_file)

# Reading from .json file
with open("jedi.json", "r") as read_file:
    data = json.load(read_file)