somes in python

#Kiem tra (a, b, c) co phai 3 canh cua 1 tam giac hay khong
def main():
    a= float(raw_input('Nhap vao canh a= '))
    b= float(raw_input('Nhap vao canh b= '))
    c= float(raw_input('Nhap vao canh c= '))

    if a+b>c and b+c>a and c+a>b:
        print "(%d, %d, %d) la 3 canh 1 tam giac :D" %(a, b, c)
    else:
        print "K phai 3 canh 1 tam giac."
if __name__ == '__main__':
    main()
----------------------------------------------

#Lap trinh doi chu thuong thanh chu hoa
def main():
    s= raw_input('Nhap vao 1 xau ky tu: ')
    print s.upper()
if __name__== '__main__':
    main()
----------------------------------------------

#Doi cho 2 bien gia tri kieu real
def main():
    a= float(raw_input('a= '))
    b= float(raw_input('b= '))
    a, b= b, a
    print a, b
if __name__== '__main__':
    main()