结肠中的结肠预期错误，一般解决方案

Question

def remove(self, allonym, phno=None):
    digit = self.encounter(allonym)
    if digit > 0:
        del self.phoneDic[digit]
        print("Removal completed!")
    elif digit = 0:                 #Colon expected error
        print("Does not exsist")
    elif digit = -1:                #Colon expected error
        if phno:
            del self.phoneDic[phno]
        else:
            print("Multiple individuals has this name, input number.")

您如何解决这些冒号预期错误？我还有其他类似情况也有相同的错误。