s = set(['Adam', 'Lisa', 'Paul'])
L = ['Adam', 'Lisa', 'Bart', 'Paul']
for x in L:
if x in s:
s.remove(x)
else:
s.add(x)
print s
L = ['Adam', 'Lisa', 'Bart', 'Paul']
for x in L:
if x in s:
s.remove(x)
else:
s.add(x)
print s
2016-06-14
def firstCharUpper(s):
return s[:1].upper()+s[1:]
print firstCharUpper('hello')
print firstCharUpper('sunday')
print firstCharUpper('september')
return s[:1].upper()+s[1:]
print firstCharUpper('hello')
print firstCharUpper('sunday')
print firstCharUpper('september')
2016-06-14
def average(*args):
if len(args)==0:
return 0.0
else:
x=sum(args)*1.0/len(args)
return x
print average()
print average(1, 2)
print average(1, 2, 2, 3, 4)
if len(args)==0:
return 0.0
else:
x=sum(args)*1.0/len(args)
return x
print average()
print average(1, 2)
print average(1, 2, 2, 3, 4)
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n=1
sum=0
while n<=100:
if n%2!=0:
sum=sum+n
n=n+1
print sum
sum=0
while n<=100:
if n%2!=0:
sum=sum+n
n=n+1
print sum
2016-06-14
注意看“注意”:name 这个变量是在 for 循环中定义的,意思是,依次取出list中的每一个元素,并把元素赋值给 name,然后执行for循环体(就是缩进的代码块)。
L = [75, 92, 59, 68]
sum = 0.0
for name in L:
sum=name+sum
print sum/4
L = [75, 92, 59, 68]
sum = 0.0
for name in L:
sum=name+sum
print sum/4
2016-06-14
这个在自己的Python运行的出来,在这里通不过。
def average(*args):
n = 0
s = 0
if args == ():
print 0
else:
for x in args:
n = n + 1
s = s + x
print float(s) / n
def average(*args):
n = 0
s = 0
if args == ():
print 0
else:
for x in args:
n = n + 1
s = s + x
print float(s) / n
2016-06-14
这里最重要的是记住这句话“Python把0、空字符串''和None看成 False,其他数值和非空字符串都看成 True”。根据这个规则,判定字符串是否空与非空,根据“短路计算”原理,就不难理解这些实例了
2016-06-14