UnboundLocalError：分配问题之前引用的局部变量

Question

class Factor:
def __init__(self, a, b, c):                                        
    self.a = a
    self.b = b
    self.c = c

def commonFactor(self):                                             
    global cfa                                                      
    cfa = self.a                                                    
    cfb = self.b
    while cfb:                                                      
        cfa, cfb = cfb, cfa % cfb                                   
    return cfa                                                      


def simplifyIntegers(self):                                         
    self.a = int(self.a / cfa)                                      
    self.b = int(self.b / cfa)
    self.c = int(self.c / cfa)
    return self.c                                                   


def coefficients(self):                                             
    if self.a == 1:                                                 
        coe1 = 1
        coe2 = 1
    else:                                                           
        coe1 = self.a
        coe2 = 1
    return self.coe1                                                


def getFactors(self):                                                
    positivec = abs(self.c)
    global result                                                   
    result = set()
    for i in range(1, int(positivec ** 0.5) + 1):
        div, mod = divmod(positivec, i)
        if mod == 0:
            result |= {i, div}
    return result                                                   


def numbers(self):                                                 
    if self.c < 0:                                                  
        poslist = [int(x) for x in result]                          
        neglist = [-(x) for x in poslist]
        numpos = poslist[0]                                         
        numneg = neglist[-1]                                       
        for i in poslist:                                           
            number = numpos + numneg                                
            poslist.remove(numpos)                                  
            neglist.remove(numneg)
            if number == self.b:                                    
                num1 = numpos
                num2 = numneg
                return num1                                         
            elif len(poslist) > 0:                                   
                numpos = poslist[0]
                numneg = neglist[-1]
            else:                                                   
                print("This equation can not be fully factored.")
    if self.c > 0:                                                   
        poslist1 = [int(x) for x in result]                         
        poslist2 = [int(x) for x in result]
        neglist1 = [-(x) for x in poslist1]
        neglist2 = [-(x) for x in poslist1]
        numpos1 = poslist1[0]
        numpos2 = poslist2[-1]
        numneg1 = neglist1[0]
        numneg2 = neglist2[-1]
        for i in poslist1:                                          
            number = numpos1 + numpos2
            poslist1.remove(numpos1)
            poslist2.remove(numpos2)
            if number == self.b:
                num1 = numpos1
                num2 = numpos2
                return num1
            elif len(poslist1) > 0:
                numpos1 = poslist1[0]
                numpos2 = poslist2[-1]
            else:
                print("This equation can not be factored.")    
        for i in neglist1:                                          
            number = numneg1 + numneg2
            neglist1.remove(numneg1)
            neglist2.remove(numneg2)
            if number == self.b:
                num1 = numneg1
                num2 = numneg2
                return num1
            elif len(neglist1) > 0:
                numpos1 = neglist1[0]
                numpos2 = neglist2[-1]
            else:
                print("This equation can not be factored.")

def factoredForm(self):                                             
    cfa = str(cfa)
    coe1 = str(coe1)
    num1 = str(num1)
    coe2 = str(coe2)
    num2 = str(num2)
    equation = (cfa,"(",coe1,"x + ",num1,")(",coe2,"x + ",num2,")")
    return equation


a = input("What is A?")                                                 
a = int(a)
b = input("What is B?")
b = int(b)
c = input("What is C?")
c = int(c)

e = Factor(a,b,c)                                                       
print(e.factoredForm())

I keep getting this error-

UnboundLocalError: local variable 'cfa' referenced before assignment

I have looked at quite a bit of things talking about how to fix it, but none of those seemed to have offered something to fix this. I have making the variables global, but that still doesn't work and anything else didn't work any better. This is my program I made to factor quadratics if you need to know what it is doing. Thanks to anyone that can help.

Answer 1

Here it looks like you are trying to create a local cfa which is a str version of the global cfa .

def factoredForm(self):                                             
    cfa = str(cfa)

You can't mix both types of access in the same scope. You should use a different name for the local variable.

Alternatively you could write the function like this

def factoredForm(self):
    return map(str, (cfa, "(", coe1, "x + " ,num1, ")(", coe2, "x + " ,num2 ,")"))

Answer 2

These statements:

cfa = str(cfa)
coe1 = str(coe1)
num1 = str(num1)
coe2 = str(coe2)
num2 = str(num2)

suggest that you want all of these variables as instance variables (not globals). I think you have find each use and change the way you access them.