>>> import this
The Zen of Python, by Tim Peters

Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
Flat is better than nested.
Sparse is better than dense.
Readability counts.
Special cases aren't special enough to break the rules.
Although practicality beats purity.
Errors should never pass silently.
Unless explicitly silenced.
In the face of ambiguity, refuse the temptation to guess.
There should be one-- and preferably only one --obvious way to do it.
Although that way may not be obvious at first unless you're Dutch.
Now is better than never.
Although never is often better than *right* now.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.
Namespaces are one honking great idea -- let's do more of those!

>>> 2 + 3 * 6
20

>>> (2 + 3) * 6
30

>>> 2 ** 8
256

>>> 23 // 7
3

>>> 23 % 7
2

>>> (5 - 1) * ((7 + 1) / (3 - 1))
16.0

>>> 'Alice' 'Bob'
'AliceBob'

>>> 'Alice' * 5
'AliceAliceAliceAliceAlice'

>>> spam = 'Hello'
>>> spam
'Hello'

>>> _spam = 'Hello'

# This is a comment

# This is a
# multiline comment

"""
This is a
multiline comment
"""

a = 1  # initialization

>>> print('Hello world!')
Hello world!

>>> a = 1
>>> print('Hello world!', a)
Hello world! 1

>>> print('What is your name?')   # ask for their name
>>> myName = input()
>>> print('It is good to meet you, {}'.format(myName))
What is your name?
Al
It is good to meet you, Al

>>> len('hello')
5

>>> a = [1, 2, 3]
>>> if a:
>>>     print("the list is not empty!")

>>> str(29)
'29'

>>> print('I am {} years old.'.format(str(29)))
I am 29 years old.

>>> str(-3.14)
'-3.14'

>>> int(7.7)
7

>>> int(7.7) + 1
8

>>> 42 == 42
True

>>> 40 == 42
False

>>> 'hello' == 'hello'
True

>>> 'hello' == 'Hello'
False

>>> 'dog' != 'cat'
True

>>> 42 == 42.0
True

>>> 42 == '42'
False

>>> (4 < 5) and (5 < 6)
True

>>> (4 < 5) and (9 < 6)
False

>>> (1 == 2) or (2 == 2)
True

>>> 2 + 2 == 4 and not 2 + 2 == 5 and 2 * 2 == 2 + 2
True

if name == 'Alice':
    print('Hi, Alice.')

name = 'Bob'
if name == 'Alice':
    print('Hi, Alice.')
else:
    print('Hello, stranger.')

spam = 0
while spam < 5:
    print('Hello, world.')
    spam = spam + 1

while True:
    print('Please type your name.')
    name = input()
    if name == 'your name':
        break
print('Thank you!')

while True:
    print('Who are you?')
    name = input()
    if name != 'Joe':
        continue
    print('Hello, Joe. What is the password? (It is a fish.)')
    password = input()
    if password == 'swordfish':
        break
print('Access granted.')

>>> print('My name is')
>>> for i in range(5):
>>>     print('Jimmy Five Times ({})'.format(str(i)))
My name is
Jimmy Five Times (0)
Jimmy Five Times (1)
Jimmy Five Times (2)
Jimmy Five Times (3)
Jimmy Five Times (4)

>>> for i in range(0, 10, 2):
>>>    print(i)
0
2
4
6
8

>>> for i in range(5, -1, -1):
>>>     print(i)
5
4
3
2
1
0

import random
for i in range(5):
    print(random.randint(1, 10))

import random, sys, os, math

>>> def hello(name):
>>>     print('Hello {}'.format(name))
>>>
>>> hello('Alice')
>>> hello('Bob')
Hello Alice
Hello Bob

import random
def getAnswer(answerNumber):
    if answerNumber == 1:
        return 'It is certain'
    elif answerNumber == 2:
        return 'It is decidedly so'
    elif answerNumber == 3:
        return 'Yes'
    elif answerNumber == 4:
        return 'Reply hazy try again'
    elif answerNumber == 5:
        return 'Ask again later'
    elif answerNumber == 6:
        return 'Concentrate and ask again'
    elif answerNumber == 7:
        return 'My reply is no'
    elif answerNumber == 8:
        return 'Outlook not so good'
    elif answerNumber == 9:
        return 'Very doubtful'

r = random.randint(1, 9)
fortune = getAnswer(r)
print(fortune)

>>> spam = print('Hello!')
Hello!

>>> spam is None
True

>>> print('Hello', end='')
>>> print('World')
HelloWorld

>>> print('cats', 'dogs', 'mice')
cats dogs mice

>>> print('cats', 'dogs', 'mice', sep=',')
cats,dogs,mice

>>> def spam():
>>>     global eggs
>>>     eggs = 'spam'
>>>
>>> eggs = 'global'
>>> spam()
>>> print(eggs)
spam

>>> def spam(divideBy):
>>>     try:
>>>         return 42 / divideBy
>>>     except ZeroDivisionError as e:
>>>         print('Error: Invalid argument: {}'.format(e))
>>>
>>> print(spam(2))
>>> print(spam(12))
>>> print(spam(0))
>>> print(spam(1))
21.0
3.5
Error: Invalid argument: division by zero
None
42.0

>>> spam = ['cat', 'bat', 'rat', 'elephant']

>>> spam
['cat', 'bat', 'rat', 'elephant']

>>> spam = ['cat', 'bat', 'rat', 'elephant']
>>> spam[0]
'cat'

>>> spam[1]
'bat'

>>> spam[2]
'rat'

>>> spam[3]
'elephant'

>>> spam = ['cat', 'bat', 'rat', 'elephant']
>>> spam[-1]
'elephant'

>>> spam[-3]
'bat'

>>> 'The {} is afraid of the {}.'.format(spam[-1], spam[-3])
'The elephant is afraid of the bat.'

>>> spam = ['cat', 'bat', 'rat', 'elephant']
>>> spam[0:4]
['cat', 'bat', 'rat', 'elephant']

>>> spam[1:3]
['bat', 'rat']

>>> spam[0:-1]
['cat', 'bat', 'rat']

>>> spam = ['cat', 'bat', 'rat', 'elephant']
>>> spam[:2]
['cat', 'bat']

>>> spam[1:]
['bat', 'rat', 'elephant']

>>> spam2 = spam[:]
['cat', 'bat', 'rat', 'elephant']
>>> spam.append('dog')
>>> spam
['cat', 'bat', 'rat', 'elephant', 'dog']
>>> spam2
['cat', 'bat', 'rat', 'elephant']

>>> spam = ['cat', 'dog', 'moose']
>>> len(spam)
3

>>> spam = ['cat', 'bat', 'rat', 'elephant']
>>> spam[1] = 'aardvark'

>>> spam
['cat', 'aardvark', 'rat', 'elephant']

>>> spam[2] = spam[1]

>>> spam
['cat', 'aardvark', 'aardvark', 'elephant']

>>> spam[-1] = 12345

>>> spam
['cat', 'aardvark', 'aardvark', 12345]

>>> supplies = ['pens', 'staplers', 'flame-throwers', 'binders']
>>> for supply in supplies:
>>>     print('Supplies contains: {}'.format(supply))
Supplies contains: pens
Supplies contains: staplers
Supplies contains: flame-throwers
Supplies contains: binders

>>> supplies = ['pens', 'staplers', 'flame-throwers', 'binders']
>>> for i, supply in enumerate(supplies):
>>>     print('Index {} in supplies is: {}'.format(str(i), supply))
Index 0 in supplies is: pens
Index 1 in supplies is: staplers
Index 2 in supplies is: flame-throwers
Index 3 in supplies is: binders

>>> name = ['Pete', 'John', 'Elizabeth']
>>> age = [6, 23, 44]
>>> for n, a in zip(name, age):
>>>     print('{} is {} years old'.format(n, a))
Pete is 6 years old
John is 23 years old
Elizabeth is 44 years old

>>> 'howdy' in ['hello', 'hi', 'howdy', 'heyas']
True

>>> spam = ['hello', 'hi', 'howdy', 'heyas']
>>> 'cat' in spam
False

>>> 'howdy' not in spam
False

>>> 'cat' not in spam
True

>>> cat = ['fat', 'orange', 'loud']

>>> size = cat[0]

>>> color = cat[1]

>>> disposition = cat[2]

>>> cat = ['fat', 'orange', 'loud']

>>> size, color, disposition = cat

>>> a, b = 'Alice', 'Bob'
>>> a, b = b, a
>>> print(a)
'Bob'

>>> print(b)
'Alice'

>>> spam = 'Hello'
>>> spam += ' world!'
>>> spam
'Hello world!'

>>> bacon = ['Zophie']
>>> bacon *= 3
>>> bacon
['Zophie', 'Zophie', 'Zophie']

>>> spam = ['cat', 'dog', 'bat']

>>> spam.append('moose')

>>> spam
['cat', 'dog', 'bat', 'moose']

myCat = {'size': 'fat', 'color': 'gray', 'disposition': 'loud'}

>>> for i in spam.items():
>>>     print(i)
('color', 'red')
('age', 42)

>>> spam = {'color': 'red', 'age': 42}
>>>
>>> for k, v in spam.items():
>>>     print('Key: {} Value: {}'.format(k, str(v)))
Key: age Value: 42
Key: color Value: red

>>> spam = {'name': 'Zophie', 'age': 7}

>>> 'color' in spam
False

>>> 'color' not in spam
True

>>> print("Hello there!\nHow are you?\nI\'m doing fine.")
Hello there!
How are you?
I'm doing fine.

>>> print('''Dear Alice,
>>>
>>> Eve's cat has been arrested for catnapping, cat burglary, and extortion.
>>>
>>> Sincerely,
>>> Bob''')
Dear Alice,

Eve's cat has been arrested for catnapping, cat burglary, and extortion.

Sincerely,
Bob

>>> spam = 'Hello world!'

>>> spam[0]
'H'

>>> spam[4]
'o'

>>> spam[-1]
'!'

>>> spam[0:5]
'Hello'

>>> spam[:5]
'Hello'

>>> spam[6:]
'world!'

>>> spam[6:-1]
'world'

>>> spam[:-1]
'Hello world'

>>> spam[::-1]
'!dlrow olleH'

>>> spam = 'Hello world!'
>>> fizz = spam[0:5]
>>> fizz
'Hello'

>>> 'Hello' in 'Hello World'
True

>>> 'Hello' in 'Hello'
True

>>> 'HELLO' in 'Hello World'
False

>>> '' in 'spam'
True

>>> 'cats' not in 'cats and dogs'
False

>>> a = [1, 2, 3, 4]
>>> 5 in a
False

>>> 2 in a
True

>>> spam = 'Hello world!'
>>> spam = spam.upper()
>>> spam
'HELLO WORLD!'

>>> spam = spam.lower()
>>> spam
'hello world!'

>>> ', '.join(['cats', 'rats', 'bats'])
'cats, rats, bats'

>>> ' '.join(['My', 'name', 'is', 'Simon'])
'My name is Simon'

>>> 'ABC'.join(['My', 'name', 'is', 'Simon'])
'MyABCnameABCisABCSimon'

>>> 'My name is Simon'.split()
['My', 'name', 'is', 'Simon']

>>> 'MyABCnameABCisABCSimon'.split('ABC')
['My', 'name', 'is', 'Simon']

>>> 'My name is Simon'.split('m')
['My na', 'e is Si', 'on']

>>> name = 'Pete'
>>> 'Hello %s' % name
"Hello Pete"

>>> num = 5
>>> 'I have %x apples' % num
"I have 5 apples"

>>> name = 'John'
>>> age = 20'

>>> "Hello I'm {}, my age is {}".format(name, age)
"Hello I'm John, my age is 20"

>>> "Hello I'm {0}, my age is {1}".format(name, age)
"Hello I'm John, my age is 20"

>>> name = 'Elizabeth'
>>> f'Hello {name}!'
'Hello Elizabeth!

>>> a = 5
>>> b = 10
>>> f'Five plus ten is {a + b} and not {2 * (a + b)}.'
'Five plus ten is 15 and not 30.'

>>> import os

>>> os.path.join('usr', 'bin', 'spam')
'usr\\bin\\spam'

>>> from pathlib import Path

>>> print(Path('usr').joinpath('bin').joinpath('spam'))
usr/bin/spam

>>> from pathlib import Path

>>> print(Path('usr') / 'bin' / 'spam')
usr/bin/spam

>>> my_files = ['accounts.txt', 'details.csv', 'invite.docx']

>>> for filename in my_files:
>>>     print(os.path.join('C:\\Users\\asweigart', filename))
C:\Users\asweigart\accounts.txt
C:\Users\asweigart\details.csv
C:\Users\asweigart\invite.docx

>>> my_files = ['accounts.txt', 'details.csv', 'invite.docx']
>>> home = Path.home()
>>> for filename in my_files:
>>>     print(home / filename)
/home/asweigart/accounts.txt
/home/asweigart/details.csv
/home/asweigart/invite.docx

>>> import os
>>> os.path.isabs('/')
True
>>> os.path.isabs('..')
False

>>> from pathlib import Path
>>> Path('/').is_absolute()
True
>>> Path('..').is_absolute()
False

>>> import os
>>> os.getcwd()
'/home/asweigart'
>>> os.path.abspath('..')
'/home'

from pathlib import Path
print(Path.cwd())
/home/asweigart
print(Path('..').resolve())
/home

>>> import os
>>> os.path.relpath('/etc/passwd', '/')
'etc/passwd'

>>> from pathlib import Path
>>> print(Path('/etc/passwd').relative_to('/'))
etc/passwd

>>> with open('C:\\Users\\your_home_folder\\hello.txt') as hello_file:
...     hello_content = hello_file.read()
>>> hello_content
'Hello World!'

>>> # Alternatively, you can use the *readlines()* method to get a list of string values from the file, one string for each line of text:

>>> with open('sonnet29.txt') as sonnet_file:
...     sonnet_file.readlines()
[When, in disgrace with fortune and men's eyes,\n', ' I all alone beweep my
outcast state,\n', And trouble deaf heaven with my bootless cries,\n', And
look upon myself and curse my fate,']

>>> # You can also iterate through the file line by line:
>>> with open('sonnet29.txt') as sonnet_file:
...     for line in sonnet_file: # note the new line character will be included in the line
...         print(line, end='')

When, in disgrace with fortune and men's eyes,
I all alone beweep my outcast state,
And trouble deaf heaven with my bootless cries,
And look upon myself and curse my fate,

>>> with open('bacon.txt', 'w') as bacon_file:
...     bacon_file.write('Hello world!\n')
13

>>> with open('bacon.txt', 'a') as bacon_file:
...     bacon_file.write('Bacon is not a vegetable.')
25

>>> with open('bacon.txt') as bacon_file:
...     content = bacon_file.read()

>>> print(content)
Hello world!
Bacon is not a vegetable.

import json
with open("filename.json", "r") as f:
    content = json.loads(f.read())

import json

content = {"name": "Joe", "age": 20}
with open("filename.json", "w") as f:
    f.write(json.dumps(content, indent=2))

from ruamel.yaml import YAML

with open("filename.yaml") as f:
    yaml=YAML()
    yaml.load(f)

>>> raise Exception('This is the error message.')
Traceback (most recent call last):
  File "<pyshell#191>", line 1, in <module>
    raise Exception('This is the error message.')
Exception: This is the error message.

def box_print(symbol, width, height):
    if len(symbol) != 1:
      raise Exception('Symbol must be a single character string.')
    if width <= 2:
      raise Exception('Width must be greater than 2.')
    if height <= 2:
      raise Exception('Height must be greater than 2.')
    print(symbol * width)
    for i in range(height - 2):
        print(symbol + (' ' * (width - 2)) + symbol)
    print(symbol * width)
for sym, w, h in (('*', 4, 4), ('O', 20, 5), ('x', 1, 3), ('ZZ', 3, 3)):
    try:
        box_print(sym, w, h)
    except Exception as err:
        print('An exception happened: ' + str(err))

def forward(f, *args, **kwargs):
    return f(*args, **kwargs)

>>> def fruits(*args):
>>>    for fruit in args:
>>>       print(fruit)

>>> fruits("apples", "bananas", "grapes")

"apples"
"bananas"
"grapes"

>>> def fruit(**kwargs):
>>>    for key, value in kwargs.items():
>>>        print("{0}: {1}".format(key, value))

>>> fruit(name = "apple", color = "red")

name: apple
color: red

>>> def show(arg1, arg2, *args, kwarg1=None, kwarg2=None, **kwargs):
>>>   print(arg1)
>>>   print(arg2)
>>>   print(args)
>>>   print(kwarg1)
>>>   print(kwarg2)
>>>   print(kwargs)

>>> data1 = [1,2,3]
>>> data2 = [4,5,6]
>>> data3 = {'a':7,'b':8,'c':9}

>>> show(*data1,*data2, kwarg1="python",kwarg2="cheatsheet",**data3)
1
2
(3, 4, 5, 6)
python
cheatsheet
{'a': 7, 'b': 8, 'c': 9}

>>> show(*data1, *data2, **data3)
1
2
(3, 4, 5, 6)
None
None
{'a': 7, 'b': 8, 'c': 9}

# If you do not specify ** for kwargs
>>> show(*data1, *data2, *data3)
1
2
(3, 4, 5, 6, "a", "b", "c")
None
None
{}

>>> with open(filename) as f:
>>>     file_contents = f.read()

# the open_file object has automatically been closed.

>>> if __name__ == "__main__":
...     # execute only if run as a script
...     main()

>>> # Python program to execute function directly
>>> def add(a, b):
...     return a+b
...
>>> add(10, 20) # we can test it by calling the function save it as calculate.py
30
>>> # Now if we want to use that module by importing we have to comment out our call,
>>> # Instead we can write like this in calculate.py
>>> if __name__ == "__main__":
...     add(3, 5)
...
>>> import calculate
>>> calculate.add(3, 5)
8