Python: simple code

# !/usr/bin/env python3.6 
# -*- coding: utf-8 -*- 
# visual studio 2017
# 2019 10 12 Geovin Du print
from turtle import *;
import sys;
from math import ceil;
import re;
import time;
import operator;
from copy import deepcopy;
from random import randint;



print(‘geovindu‘);

# 重复元素判定
def all_unique(lst):
    return len(lst) == len(set(lst))
x = [1,1,2,2,3,2,3,4,5,6]
y = [1,2,3,4,5]
all_unique(x) # False
all_unique(y) # True

# #字符元素组成判定
from collections import Counter
def anagram(first, second):
   return Counter(first) == Counter(second)
anagram("abcd3", "3acdb") # True
#内存占用
variable = 30 
print(sys.getsizeof(variable)) # 24
#字节占用
def byte_size(string):
    return(len(string.encode(‘utf-8‘)))

byte_size(‘??‘) # 4
byte_size(‘Hello World‘) # 11  
#打印 N 次字符串
n = 2; 
s ="Programming"; 
print(s * n);
# ProgrammingProgramming 
#大写第一个字母
s = "programming is awesome"
print(s.title())
# Programming Is Awesome
#压缩
def compact(lst):
    return list(filter(bool, lst))

compact([0, 1, False, 2, ‘‘, 3, ‘a‘, ‘s‘, 34])
# [ 1, 2, 3, ‘a‘, ‘s‘, 34 ]

#解包
array = [[‘a‘, ‘b‘], [‘c‘, ‘d‘], [‘e‘, ‘f‘]]
transposed = zip(*array)
print(transposed)
# [(‘a‘, ‘c‘, ‘e‘), (‘b‘, ‘d‘, ‘f‘)]

#分块
def chunk(lst, size):
    return list(
        map(lambda x: lst[x * size:x * size + size],
            list(range(0, ceil(len(lst) / size)))))

#链式对比
a = 3
print( 2 < a < 8) # True
print(1 == a < 2) # False



# print(len(re.findall(r‘[aeiou]‘, ‘foobar‘, re.IGNORECASE)));

#元音统计
def count_vowels(str):
    return len(re.findall(r‘[aeiou]‘, str, re.IGNORECASE))


print(‘Geovin Du  foobar中有多少个元音字母：‘+str(count_vowels(‘Geovin Du foobar‘))) # 3
print(‘gym中有多少个元音字母：‘+str(count_vowels(‘gym‘))) # 0

chunk([1,2,3,4,5],2)
# [[1,2],[3,4],5]

#首字母小写
def decapitalize(string):
    return string[:1].lower() + string[1:]

print(‘FooBar:‘+decapitalize(‘FooBar‘)); # ‘fooBar‘

def get_str(oriStr,splitStr):
     str_list = oriStr.split(splitStr)
     if len(str_list) > 1:
         for index in range(1, len(str_list)):
             if str_list[index] != ‘‘:
                 str_list[index] = str_list[index][0].upper() + str_list[index][1:]
             else:
                 continue
         return ‘‘.join(str_list)
     else:
         return oriStr

print(‘hello_for_our_world:‘+get_str(‘hello_for_our_world‘,‘_‘));


#展开列表
def spread(arg):
    ret = []
    for i in arg:
        if isinstance(i, list):
            ret.extend(i)
        else:
            ret.append(i)
    return ret

def deep_flatten(lst):
    result = []
    result.extend(
        spread(list(map(lambda x: deep_flatten(x) if type(x) == list else x, lst))))
    return result


deep_flatten([1, [2], [[3], 4], 5]) # [1,2,3,4,5]
#列表的差
def difference(a, b):
    set_a = set(a)
    set_b = set(b)
    comparison = set_a.difference(set_b)
    return list(comparison)


difference([1,2,3], [1,2,4]) # [3]

#通过函数取差
def difference_by(a, b, fn):
    b = set(map(fn, b))
    return [item for item in a if fn(item) not in b]


from math import floor
difference_by([2.1, 1.2], [2.3, 3.4],floor) # [1.2]
difference_by([{ ‘x‘: 2 }, { ‘x‘: 1 }], [{ ‘x‘: 1 }], lambda v : v[‘x‘])
# [ { x: 2 } ]
#链式函数调用
def add(a, b):
    return a + b

def subtract(a, b):
    return a - b

a, b = 4, 5
print((subtract if a > b else add)(a, b)) # 9 

#检查重复项
def has_duplicates(lst):
    return len(lst) != len(set(lst))


x = [1,2,3,4,5,5]
y = [1,2,3,4,5]
has_duplicates(x) # True
has_duplicates(y) # False

#合并两个字典
def merge_two_dicts(a, b):
    c = a.copy()   # make a copy of a 
    c.update(b)    # modify keys and values of a with the ones from b
    return c


a = { ‘x‘: 1, ‘y‘: 2}
b = { ‘y‘: 3, ‘z‘: 4}
print(merge_two_dicts(a, b))
# {‘y‘: 3, ‘x‘: 1, ‘z‘: 4}


#3.5
def merge_dictionaries(a, b):
     return {**a, **b}

a = { ‘x‘: 1, ‘y‘: 2}
b = { ‘y‘: 3, ‘z‘: 4}
print(merge_dictionaries(a, b))
# {‘y‘: 3, ‘x‘: 1, ‘z‘: 4}

#将两个列表转化为字典
def to_dictionary(keys, values):
    return dict(zip(keys, values))


keys = ["a", "b", "c"]    
values = [2, 3, 4]
print(to_dictionary(keys, values))
# {‘a‘: 2, ‘c‘: 4, ‘b‘: 3}

#使用枚举
listd = ["a", "b", "c", "d"]
for index, element in enumerate(listd): 
    print("Value", element, "Index ", index, )

# (‘Value‘, ‘a‘, ‘Index ‘, 0)
# (‘Value‘, ‘b‘, ‘Index ‘, 1)
#(‘Value‘, ‘c‘, ‘Index ‘, 2)
# (‘Value‘, ‘d‘, ‘Index ‘, 3) 

# 执行时间
start_time = time.time()

a = 1
b = 2
c = a + b
print(c) #3

end_time = time.time()
total_time = end_time - start_time
print("Time: ", total_time)

# (‘Time: ‘, 1.1205673217773438e-05)
#Try else
try:
    2*3
except TypeError:
    print("An exception was raised")
else:
    print("Thank God, no exceptions were raised.")

#Thank God, no exceptions were raised.

#元素频率
def most_frequent(listd):
    return max(set(listd), key = listd.count)


listd = [1,2,1,2,3,2,1,4,2]
most_frequent(listd)

#回文序列
def palindrome(string):
    from re import sub
    s = sub(‘[\W_]‘, ‘‘, string.lower())
    return s == s[::-1]


palindrome(‘taco cat‘) # True

#不使用 if-else 的计算子
action = {
    "+": operator.add,
    "-": operator.sub,
    "/": operator.truediv,
    "*": operator.mul,
    "**": pow
}
print(action[‘-‘](50, 25)) # 25

#Shuffle 该算法会打乱列表元素的顺序，它主要会通过 Fisher-Yates 算法对新列表进行排序
def shuffle(lst):
    temp_lst = deepcopy(lst)
    m = len(temp_lst)
    while (m):
        m -= 1
        i = randint(0, m)
        temp_lst[m], temp_lst[i] = temp_lst[i], temp_lst[m]
    return temp_lst


foo = [1,2,3]
shuffle(foo) # [2,3,1] , foo = [1,2,3]

#展开列表

def spread(arg):
    ret = []
    for i in arg:
        if isinstance(i, list): #
            ret.extend(i)
        else:
            ret.append(i)
    return ret


print(‘展开列表：‘+str(spread([1,2,3,[4,5,6],[7],8,9]))); # [1,2,3,4,5,6,7,8,9]

#交换值
def swap(a, b):
  return b, a

a, b = -1, 14
swap(a, b) # (14, -1)
spread([1,2,3,[4,5,6],[7],8,9]) # [1,2,3,4,5,6,7,8,9]

#字典默认值
d = {‘a‘: 1, ‘b‘: 2}

print(d.get(‘c‘, 3)) # 3




#畫圖形
#https://github.com/asweigart/simple-turtle-tutorial-for-python
for i in range(500): # this "for" loop will repeat these functions 500 times
    forward(i)
    left(91)