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#!/usr/bin/env PYTHONHASHSEED=1234 python3

# Copyright 2014-2019 Brett Slatkin, Pearson Education Inc.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

# Reproduce book environment

import random

random.seed(1234)

import logging

from pprint import pprint

from sys import stdout as STDOUT

# Write all output to a temporary directory

import atexit

import gc

import io

import os

import tempfile

TEST_DIR = tempfile.TemporaryDirectory()

atexit.register(TEST_DIR.cleanup)

# Make sure Windows processes exit cleanly

OLD_CWD = os.getcwd()

atexit.register(lambda: os.chdir(OLD_CWD))

os.chdir(TEST_DIR.name)

def close_open_files():

everything = gc.get_objects()

for obj in everything:

if isinstance(obj, io.IOBase):

obj.close()

atexit.register(close_open_files)

# Example 1

def get_stats(numbers):

minimum = min(numbers)

maximum = max(numbers)

return minimum, maximum

lengths = [63, 73, 72, 60, 67, 66, 71, 61, 72, 70]

minimum, maximum = get_stats(lengths) # Two return values

print(f'Min: {minimum}, Max: {maximum}')

# Example 2

first, second = 1, 2

assert first == 1

assert second == 2

def my_function():

return 1, 2

first, second = my_function()

assert first == 1

assert second == 2

# Example 3

def get_avg_ratio(numbers):

average = sum(numbers) / len(numbers)

scaled = [x / average for x in numbers]

scaled.sort(reverse=True)

return scaled

longest, *middle, shortest = get_avg_ratio(lengths)

print(f'Longest: {longest:>4.0%}')

print(f'Shortest: {shortest:>4.0%}')

# Example 4

def get_stats(numbers):

minimum = min(numbers)

maximum = max(numbers)

count = len(numbers)

average = sum(numbers) / count

sorted_numbers = sorted(numbers)

middle = count // 2

if count % 2 == 0:

lower = sorted_numbers[middle - 1]

upper = sorted_numbers[middle]

median = (lower + upper) / 2

else:

median = sorted_numbers[middle]

return minimum, maximum, average, median, count

minimum, maximum, average, median, count = get_stats(lengths)

print(f'Min: {minimum}, Max: {maximum}')

print(f'Average: {average}, Median: {median}, Count {count}')

assert minimum == 60

assert maximum == 73

assert average == 67.5

assert median == 68.5

assert count == 10

# Verify odd count median

_, _, _, median, count = get_stats([1, 2, 3])

assert median == 2

assert count == 3

# Example 5

# Correct:

minimum, maximum, average, median, count = get_stats(lengths)

# Oops! Median and average swapped:

minimum, maximum, median, average, count = get_stats(lengths)

# Example 6

minimum, maximum, average, median, count = get_stats(

lengths)

minimum, maximum, average, median, count = \

get_stats(lengths)

(minimum, maximum, average,

median, count) = get_stats(lengths)

(minimum, maximum, average, median, count

) = get_stats(lengths)