def myabs(x):

    if x>0:

        return x

    else:

        return -x

f = lambda x,y,z:x+y+z

print(f(1,2,3)) #

L = [(lambda x:x**2),(lambda x:x**3)]

print(L[0](3),L[1](3)) #(9, 27)

class Car:

    def infor(self):

        print("This is a car")

car = Car()

car.infor() #This is a car

s = "hello world"

with open('sample.txt','a+') as f:

    f.write(s)

f = open('sample.txt','r')

print(fp.read(5)) #读取前5字节

f = open('sample.txt','r')

while True:

    line = f.readline()

    if line=='':

        break

    print line,

    f.close()