PYTHON---生成式
1.列表生成式
s = '51 5000 10000'
li = []
for item in s.split():
li.append(int(item))
k,a,b = li
k, a, b = [int(item) for item in s.split()]
print k,a,b
2.生成一個列表，列表元素分別為[1**2,2**2,3**2,4**2...n**2]
li = []
for i in range(1, 8):
li.append(i ** 2)
print li
print [i ** 2 for i in range(1, 8)]
print [i ** 2 for i in range(1, 8) if i % 2 == 0]
import math
# 1.找出1~10之間的所有偶數，並且返回一個列表(包含以這個偶數為半徑的圓的面積)
li = []
for r in range(2, 11, 2): # [2,4,6,8,10]
square = math.pi * r * r
li.append(square)
print li
print [math.pi * r * r for r in range(2, 11, 2)]
# 2.找出1～10之間的所有奇數，並且返回一個列表(所有的奇數轉換為字串)
print [str(r) for r in range(1,11,2)]
#3.找出1～num之間的所有質數
def isPrime(num):
for i in range(2,num):
if num % i == 0:
return False
else:
return True
print [i for i in range(2,101) if isPrime(i)]
2.字典生成式
#1.假設有20個學生，學分在60～100之間，篩選出成績在90分以上的學生
import random
stuInfo = {}
for i in range(20):
name = 'westos' + str(i)
score = random.randint(60,100)
stuInfo[name] = score
stuInfo['westos'+str(i)] = random.randint(60,100)
hightscore = {}
for name,score in stuInfo.items():
if score > 90:
hightscore[name] = score
print hightscore
stuInfo = {'westos'+ str(i):random.randint(60,100) for i in range(20)}
print {name:score for name,score in stuInfo.items() if score >90}
# 2.將字典中的key值和value值調換
d = {'a':'apple','b':'bob','c':'cat'}
print {v:k for k,v in d.items()}
print {k:k.upper()for k,v in d.items()}
# 3.大小寫合併，key值最終全部為小寫
d1 = {'A':10,'b':3,'a':5,'B':8,'d':1}
print {k.lower():d1.get(k.upper(),0)+d1.get(k.lower(),0)for k,v in d1.items()}