if --elif--else
x = int(input("Please enter an integer:"))
if x < 0:
x = 0
print("Negative changed to zero")
elif x == 0:
print("zero")
else:
print("more")
Python 无switch case
猜数字小游戏
from random import randint
mystery = randint(1,100)
times = 10
print("You have %s times to guess the number."%times)
def guess_number(times):
for i in range(1,times):
user_input = int(input("enter:"))
if user_input == mystery:
print("Greate,you are right, the number is %s"%mystery)
break
elif user_input > mystery:
print("Your input too big,you have %s times left"%(times-i))
elif user_input < mystery:
print("Your input too small,you have %s times left"%(times-i))
print("Game is over...")
guess_number(10)
杨辉三角形
count = int(input("enter:"))
list_a = [1]
for i in range(count):
print(list_a)
list_a.append(0)
list_a = [list_a[k] + list_a[k-1] for k in range(i+2)]#把前面的两个加起来
九九乘法表
print ('\n'.join([' '.join(['%s*%s=%-2s'%(x,y,x*y) for x in range(1,y+1)]) for y in range(1,10)]))
count
dna = 'AAVVSSSXBA'
dna_cnt = {b : dna.count(b) for b in set(dna)}
dna_cnt
function
#定义
def menu(wine, entree,dessert):
return {'wine':wine, 'entree':entree, 'dessert':dessert}
#正常输入
menu('chardonnay','chicken','cake')
#可指定参数
menu(entree='beef',dessert='bagel',wine='bordeaux')
#参数不定的时候*
def print_args(*args):
print('Positional args',args)
print_args(1,2,3,'hello')
#keyword参数**
def print_kwargs(**kwargs):
print('Keyword args:',kwargs)
print_kwargs(first = 1,second = 2)
#Keyword args: {'first': 1, 'second': 2}
#参数为函数
def answer1():
print("Answer1")
def run_something(func):
func()
run_something(answer1)
#Answer1
#函数嵌套函数
def exp_factory(n):
def exp(a):
return a**n
return exp
square = exp_factory(2)
square(3)
#相当于
exp_factory(2)(3)
#应用
from time import perf_counter
def timer_2(f):
def _f(*args):
t0 = perf_counter()
f(*args)
return perf_counter() - t0
return _f
#匿名函数
double = lambda x:x*2
double(5)
#filter
my_list = [1,5,4,6,8,11,3,12]
new_list = list(filter(lambda x: (x%2 == 0), my_list))#将偶数过滤出来
new_list
#map
items = [1,2,3,4,5]
squred = list(map(lambda x: x**2, items))
#对每一个元素做同样的操作
squred