# coding = utf-8
# 1 line: Output
print('Hello, world!')
# 2 lines: Input, assignment
#name = input('What is your name?
')
name = 'Lius'
print('Hi, %s.' % name)
# 3 lines: For loop, built-in enumerate function, new style formatting
friends = ['john', 'pat', 'gary', 'michael']
for i, name in enumerate(friends):
print("iteration {iteration} is {name}".format(iteration=i, name=name))
# 4 lines: Fibonacci, tuple assignment
parents, babies = (1, 1)
while babies < 100:
print('This generation has {0} babies'.format(babies))
parents, babies = (babies, parents + babies)
# 5 lines: Functions
def greet(name):
print('Hello', name)
greet('Jack')
greet('Jill')
greet('Bob')
# 6 lines: Import, regular expressions
import re
for test_string in ['555-1212', 'ILL-EGAL']:
if re.match(r'^d{3}-d{4}$', test_string):
print(test_string, 'is a valid US local phone number')
else:
print(test_string, 'rejected')
# 7 lines: Dictionaries, generator expressions
prices = {'apple': 0.40, 'banana': 0.50}
my_purchase = {
'apple': 1,
'banana': 6
}
grocery_bill = sum(prices[fruit] * my_purchase[fruit]
for fruit in my_purchase)
print('I owe the grocer $%.2f' % grocery_bill)
# 8 lines: Command line arguments, exception handling
# This program adds up integers in the command line
import sys
try:
total = sum(int(arg) for arg in sys.argv[1:])
print('sum = ', total)
except ValueError:
print('Please supply integer arguments')
# 9 lines: Opening files
# indent your Python code to put into an email
import glob
# glob supports Unix style pathname extensions
# python_files = glob.glob('*.py')
# for file_name in sorted(python_files):
# print(' ------' + file_name)
#
# with open(file_name,encoding='utf-8') as f:
# for line in f:
# print(' ' + line.rstrip())
# print()
# 10 lines: Time, conditions, from..import, for..else
from time import localtime
activities = {8: 'Sleeping',
9: 'commuting',
17: 'Working',
18: 'Commuting',
20: 'Eating',
22: 'Resting' }
time_now = localtime()
hour = time_now.tm_hour
for activity_time in sorted(activities.keys()):
if hour < activity_time:
print(activities[activity_time])
break
else:
print('Unknown, AFK or sleeping!')
# 11 lines: Triple-quoted strings, while loop
REFRAIN = '''
%d bottles of beer on the wall,
%d bottles of beer,
take one down, pass it around,
%d bottles of beer on the wall!
'''
bottles_of_beer = 3
while bottles_of_beer > 1:
print(REFRAIN % (bottles_of_beer, bottles_of_beer, bottles_of_beer - 1))
bottles_of_beer -= 1
# 12 lines: Classes
class BankAccount(object):
def __init__(self, initial_balance=0):
self.balance = initial_balance
def deposit(self, amount):
self.balance += amount
def withdraw(self, amount):
self.balance -= amount
def overdrawn(self):
return self.balance < 0
my_account = BankAccount(15)
my_account.withdraw(5)
print(my_account.balance)
# 13 lines: Unit testing with unittest
import unittest
def median(pool):
copy = sorted(pool)
size = len(copy)
if size % 2 == 1:
"""
list indices must be integers or slices, not float
When you do x / y, an integer is returned in Python 2.x because the decimal is truncated
(floor division).However in 3.x, the / operator performs 'true' division,resulting in a float
instead of an integer (e.g. 1 / 2 = 0.5).Therefore you may first want to try using
middle = (first + last) // 2, adjusting so that the result returns what you expect.
"""
return copy[(size - 1) // 2]
else:
return (copy[size//2 - 1] + copy[size//2]) // 2
class TestMedian(unittest.TestCase):
def testMedian(self):
self.failUnlessEqual(median([2, 9, 9, 7, 9, 2, 4, 5, 8]), 7)
if __name__ == '__main__':
unittest.main()
# 14 lines: Doctest-based testing
def median(pool):
'''Statistical median to demonstrate doctest.
>>> median([2, 9, 9, 7, 9, 2, 4, 5, 8])
7
'''
copy = sorted(pool)
size = len(copy)
if size % 2 == 1:
return copy[(size - 1) // 2]
else:
return (copy[size // 2 - 1] + copy[size // 2]) // 2
if __name__ == '__main__':
import doctest
doctest.testmod()
# 15 lines: itertools
from itertools import groupby
lines = '''
This is the
first paragraph.
This is the second.
'''.splitlines()
# Use itertools.groupby and bool to return groups of consecutive lines that either have content or don't.
for has_chars, frags in groupby(lines, bool):
if has_chars:
print(' '.join(frags))
# PRINTS:
# This is the first paragraph.
# This is the second.
# 16 lines: csv module, tuple unpacking, cmp() built-in
import csv,operator
# write stocks data as comma-separated values
writer = csv.writer(open('stocks.csv', 'wb', buffering=0))
writer.writerows([
('GOOG', 'Google, Inc.', 505.24, 0.47, 0.09),
('YHOO', 'Yahoo! Inc.', 27.38, 0.33, 1.22),
('CNET', 'CNET Networks, Inc.', 8.62, -0.13, -1.49)
])
# read stocks data, print status messages
# Python 3.X 的版本中已经没有 cmp 函数，如果你需要实现比较功能，需要引入 operator 模块
stocks = csv.reader(open('stocks.csv', 'rb'))
status_labels = {-1: 'down', 0: 'unchanged', 1: 'up'}
for ticker, name, price, change, pct in stocks:
status = status_labels[operator.eq(float(change), 0.0)]
print('%s is %s (%s%%)' % (name, status, pct))
# 18 lines: 8-Queens Problem(recursion)
BOARD_SIZE = 8
def under_attack(col, queens):
left = right = col
for r, c in reversed(queens):
left, right = left - 1, right + 1
if c in (left, col, right):
return True
return False
def solve(n):
if n == 0:
return [[]]
smaller_solutions = solve(n - 1)
return [solution+[(n,i+1)]
# xrange() 在Python3 中为 range()
for i in range(BOARD_SIZE)
for solution in smaller_solutions
if not under_attack(i+1, solution)]
for answer in solve(BOARD_SIZE):
print(answer)
# 20 lines: Prime numbers sieve w/fancy generators
import itertools
def iter_primes():
# an iterator of all numbers between 2 and +infinity
numbers = itertools.count(2)
# generate primes forever
while True:
# get the first number from the iterator (always a prime)
prime = numbers.__next__()
yield prime
# this code iteratively builds up a chain of filters...slightly tricky, but ponder it a bit
numbers = itertools.ifilter(prime.__rmod__, numbers)
for p in iter_primes():
if p > 1000:
break
print(p)
# 21 lines: XML/HTML parsing(using Python 2.5 or third-party library)
dinner_recipe = '''<html><body><table>
<tr><th>amt</th><th>unit</th><th>item</th></tr>
<tr><td>24</td><td>slices</td><td>baguette</td></tr>
<tr><td>2+</td><td>tbsp</td><td>olive oil</td></tr>
<tr><td>1</td><td>cup</td><td>tomatoes</td></tr>
<tr><td>1</td><td>jar</td><td>pesto</td></tr>
</table></body></html>'''
# In Python 2.5 or from http://effbot.org/zone/element-index.htm
import xml.etree.ElementTree as etree
tree = etree.fromstring(dinner_recipe)
# For invalid HTML use http://effbot.org/zone/element-soup.htm
# import ElementSoup, StringIO
# tree = ElementSoup.parse(StringIO.StringIO(dinner_recipe))
pantry = set(['olive oil', 'pesto'])
for ingredient in tree.getiterator('tr'):
amt, unit, item = ingredient
if item.tag == "td" and item.text not in pantry:
print("%s: %s %s" % (item.text, amt.text, unit.text))
# 28 lines: 8-Queens Problem(define your own exceptions)
BOARD_SIZE = 8
class BailOut(Exception):
pass
def validate(queens):
left = right = col = queens[-1]
for r in reversed(queens[:-1]):
left, right = left-1, right+1
if r in (left, col, right):
raise BailOut
def add_queen(queens):
for i in range(BOARD_SIZE):
test_queens = queens + [i]
try:
validate(test_queens)
if len(test_queens) == BOARD_SIZE:
return test_queens
else:
return add_queen(test_queens)
except BailOut:
pass
raise BailOut
queens = add_queen([])
print (queens)
print ("
".join(". "*q + "Q " + ". "*(BOARD_SIZE-q-1) for q in queens))
# 33 lines: "Guess the Number" Game
import random
guesses_made = 0
name = input('Hello! What is your name?
')
number = random.randint(1, 20)
print ('Well, {0}, I am thinking of a number between 1 and 20.'.format(name))
while guesses_made < 6:
guess = int(input('Take a guess: '))
guesses_made += 1
if guess < number:
print ('Your guess is too low.')
if guess > number:
print ('Your guess is too high.')
if guess == number:
break
if guess == number:
print ('Good job, {0}! You guessed my number in {1} guesses!'.format(name, guesses_made))
else:
print ('Nope. The number I was thinking of was {0}'.format(number))