调用函数为Python中循环的每次迭代获取新值

Question

I have written a function, getSteps() which uses the random package, which should return a different value each time (it does when I run the function multiple times manually).

But when I call it inside a for loop or while loop, the script just calls the function once and then uses the value returned for the first iteration for each iteration thereafter.

I am attempting to call the function as follows:

F = open("outFile.txt","w")
for i in range(6,100):  ## for each of these values
    for j in range(0,100):  ## call the function 100 times
        steps = getSteps(i)
        F.write(str(i)+","+str(steps)+"\n")

It should have a different value for each iteration, but I find each is the same. Could anyone tell me how to fix this?

The function is defined as below:

def getSteps(maxSteps):
    global numberSteps, numberAttempts, found
    while (found == False):
        sourceJar = psj[random.randrange(0, len(psj))]
        if sourceJar in pdj:
            pdj.remove(sourceJar)
        destJar = pdj[random.randrange(0, len(pdj))]
        if sourceJar == 8 and destJar == 5:
            etf()
        elif sourceJar == 8 and destJar == 3:
            ett()
        elif sourceJar == 5 and destJar == 8:
            fte()
        elif sourceJar == 5 and destJar == 3:
            ftt()
        elif sourceJar == 3 and destJar == 8:
            tte()
        elif sourceJar == 3 and destJar == 5:
            ttf()
        found = checkFound()
        outString = "Pour the " + str(sourceJar) + " litre jar into the " + str(
            destJar) + " litre jar. The volumes for each jar are now "
        outString += "8-" + str(jar8volume) + ",5-" + str(jar5volume) + ",3-" + str(jar3volume)
        ##print outString
        updateLists()
        if (numberSteps >= maxSteps):
            numberAttempts += 1
            reset()
            ##print "Currently on iteration number " + str(numberAttempts)
        numberSteps += 1

    return numberAttempts + 1

Answer 1

There's a lot of code you're not showing. But presumably the problem is that you use global variables inside getSteps ; once found is set to True on the first invocation, it will remain true and none of the code inside the if block will execute on subsequent calls.