def print_num(arr, target):
if not arr:
return None
arr_list = list(arr)
arr = arr_list.sort()
start = 0
end = len(arr_list) - 1
while start < end:
if arr_list[start] + arr_list[end] == target:
print(str(arr_list[start]) + ',' + str(arr_list[end]))
start += 1
elif arr_list[start] + arr_list[end] > target:
end -= 1
elif arr_list[start] + arr_list[end] < target:
start += 1
test_arr = {10, 5, 6, 7, 2, 8, 1, 9, 14}
print_num(test_arr, 15)
class TestStack(object):
def __init__(self):
self.array = [[], []]
def push_a(self, data):
self.array[0].append(data)
def pop_a(self):
if len(self.array[0]) == 0:
print('a')
else:
self.array[0].pop()
def push_b(self, data):
self.array[1].append(data)
def pop_b(self):
if len(self.array[1]) == 0:
print(' b ')
else:
self.array[1].pop()
def push_c(self, data):
self.array[2].append(data)
def pop_c(self):
if len(self.array[2]) == 0:
print('c')
else:
self.array[2].pop()
def show(self):
if len(self.array[0]) == 0:
print('a')
else:
print('a:', self.array[0])
if len(self.array[1]) == 0:
print('b')
else:
print(' b:', self.array[1])
if len(self.array[2]) == 0:
print('c')
else:
print(' c:', self.array[2])
3.1 select * from A a inner join B b on a.id_a=b.id_b
3.2 select * from A a right join B b on a.id_a=b.id_b where a.id_a is NUll
3.3 select * from A a right join B b on a.id_a=b.id_b union select * from A a left join B b on a.id_a=b.id_b
输入 string="How are you！"，输出string=“you are How”
string="How are you!"
list=[]
tmp=""
for s in string:
if s!=' ':
tmp+=s
else:
list.append(tmp)
tmp=' '
list=reversed(list)
print(' '+.join(list)+'!')
输入 s='1234567890' 输出s=“$1,234,567,890”
a = '1234567890'
def test(a):
if len(a)>=3:return test(a[:-3])+','+a[-3:]
else: return '$'+a[-3:]
print(test(a))