Python修改指定格式文档

#读取两行 删除'卡号：'和 '卡密：'
#保存到数组中 ' ' 隔开然后输出
f = open('E:\\test1.txt')
done = 0
num = []
while not done:
    aLine = f.readline().strip().replace('\n','').replace('卡号：','').replace('卡密：','')
    num.append(aLine)
    if(aLine !=''):
        done = 0
    else:
        done = 1
f.close()
a= 0
try:
    while len(num)>=a:
        print(num[a] + ' ' + num[a+1])
        a = a+2
except Exception as a:
    a = ''
    print(a)
#这里实在解决不了索引越界异常，只能用用这种方法打马虎眼