Python笔记

最近在学Python，写了一些简单的小程序，先记录下来。。。。

# 判断狗的年龄
age = int(input("Age of the dog: "))
print()
if age < 0:
     print("This can hardly be true!")
elif age == 1:
    print("about 14 human years")
elif age == 2:
   print("about 22 human years")
elif age > 2:
    human = 22 + (age - 2) * 5
    print("Human years: ", human)

input('press Return>')

# 求和
n = 100
sum = 0
counter = 1
while counter <= n:
    sum = sum + counter
    counter += 1

print("sum of 1 umtil %d: %d" % (n, sum))

列表for循环遍历
arr = ['w', 'y', 'j']
for x in arr:
    print(x)
    if x == 'y':
        break
    else:
        print("ok")

# print不换行
arr = ['my', 'name', 'is', 'jack']
a = ''
for i in arr:
    a = a + i + ' '
print(a)

range()函数，前闭后开
for i in range(5):
    print(i)

# 使range以指定数字开始并指定不同的增量(甚至可以是负数;有时这也叫做'步长'):
for i in range(2, 10, 2):
    print(i)

# 结合range()和len()函数以遍历一个序列的索引
arr = ['my', 'name', 'is', 'jack']
for i in range(len(arr)):
    print(i, arr[i])

# 用range()创建列表
arr = list(range(5))
print(arr)

# 函数

def func(x, y):
    return x + y

print(func('2', 'x'))