Calculator V2

Is = '1 + 1 + 1 + 1'
Is=Is.split()
result = None
while (len(Is)<=3):
    x= Is[0]
    op= Is[1]
    y= Is[2]
    if type(float(x)) == float and type(float(y)) == float:
        x=float(x)
        y=float(y)
        if op in ['+','-','*','/']:
            if op =='+':
                result=x+y
            if op =='-':
                result=x-y
            if op =='*':
                result=x*y
            if op == '/':
                result=x/y
        else:
            print("wrong operator")
    else:
        print("wrong operand")
    del Is[:2]
    Is[0]=result
print (result)


result = None
Is ='1 + 1 + 1'
Is =Is.split()
while (len(Is) >=3):
    x=Is[0]
    op=Is[1]
    y=Is[2]
    if type(float(x)) == float and type(float(y)) == float:
        x=float(x)
        y=float(y)
        if op in ['+','-','*','/']:
            if op =='+':
                result=x+y
            if op =='-':
                result=x-y
            if op =='*':
                result=x*y
            if op == '/':
                result=x/y
        else:
            print("wrong operator!")
            break
    else:
        print("wrong data type")
        break
    del Is[:2]
    Is[0]=result
    if len(Is) ==2:
        print('wrong operand')
        break
    if len(Is) == 1:
        break
else:
    print("wrong operand")
print (result)


result = None
Is ='1 + 1 + 1 + 1'
Is =Is.split()
def check_float(data):
    try:
        float(data)
        return True
    except ValueError:
            print("invalid input")
            return False
while (len(Is) >=3):
    x=Is[0]
    op=Is[1]
    y=Is[2]
    if check_float(x) and check_float(y):
        x=float(x)
        y=float(y)
        if op in ['+','-','*','/']:
            if op =='+':
                result=x+y
            if op =='-':
                result=x-y
            if op =='*':
                result=x*y
            if op == '/':
                result=x/y
        else:
            print("wrong operator!")
            break
    else:
        print("wrong data type")
        break
    del Is[:2]
    Is[0]=result
    if len(Is) ==2:
        print('wrong operand')
        break
    if len(Is) == 1:
        break
else:
    print("wrong operand")
print (result)