解决Python中TypeError: unbound method 问题

今天执行了下之前写的Python接口文件，源码如下，

__author__ = 'Administrator'
#coding:utf-8
from readData import dictionary
readIt = {}
readIt = dictionary.onlyCellValue("E:\python\API\eadData.xls", "Sheet1", 1)
print readIt
for key in readIt:
    temp_list = readIt[key]
    for i in range(0, len(temp_list)):
        print "第"+(i+1)+"个参数为"+temp_list[i]

在运行时报错：TypeError: unbound method onlyCellValue() must be called with dictionary instance as first argument (got str instance instead)

后经在网上查看，发现时由于调用其他类时，未在后面添加括号，添加括号后，运行正常。这是由于未添加括号情况下，未被认为是类的实例，故报此错

改正后的：readIt = dictionary().onlyCellValue("E:\python\API\eadData.xls", "Sheet1", 1)