非类型的对象没有长度错误

Question

我编写了以下函数来将列表的元素添加到字符串中

import random 
import string 

def printmatches (word,x):
    y = len(word)
    z = [" "] *y 
    i = 0 
    while i<y:
        if word[i] == x: 
            z[i] = x 
        else:
            z[i] = " "  
        i+=1

    return (z)

def append(string,chars): ##append list to a string
    q = 0
    while q < len(string): 
        if string[q] == " " and chars[q] != " ":
            string[q] = chars[q]
        q+=1  

x = random.randint(0,55899)

def convertlist(x):
    q = " "
    a = 0
    while (a < len(x)):
        q+=x[a]
        a+=1
    return (q) 

try:
    f = open('words.txt', 'r')
    s = " "
    s = f.readline()

    L = s.split()

    word = L[x]

    f.close()

except IOError:
    print('file not found')

q=0

print word

print (printmatches('ereesvox','o') == [" "] * 8)  
current = [" "] * len(word)  
c = 0
char = " " 
while char != word and q < 3 and c <35: 
    char = raw_input (" ") 
    c+=1
    ##current.append(printmatches(word,char)) 
    append(current, printmatches(word,char)) 
    str = (append(current, printmatches(word,char)))
    if (convertlist(str) == word): 
        print 'Congratulations, you have won'
    if printmatches(word,char) == [" "]*len(word):    
        print "You have ", (2-q), " guesses left"   
        q+=1 
    if (q == 3):
        print "Game over"
    print ' '.join(current)     

x是一个列表，但当我执行代码时，它的类型被解释为非类型，我得到错误消息，因为我试图访问x中的元素并比较其长度。我如何解决这个问题

Answer 1

在使用x执行任何操作之前，请进行检查，以查看x不是None或list以外的任何其他类型。 像下面这样

def convertlist(x):
    q = " "
    a = 0
    if isinstance(x, list):
        while (a < len(x)):
            q+=x[a]
            a+=1
    return (q)