Dive into python 实例学python (1) —— 函数和测试

odbchelper.py

def buildConnectionString(params):
    """Build a connection string from a dictionary
    
    Returns string.
    """
    return ";".join(["%s=%s" % (k, v) for k, v in params.items()])

if __name__ == "__main__":
    myParams = {"server":"mpilgrim", 
                "database":"master", 
                "uid":"sa", 
                "pwd":"secret"
                }
    print buildConnectionString(myParams)

1、'''...'''是docstring

2、join()函数是连接字符串，这里用";"分号来连接，参数是字符串列表list。

测试代码：

odbchelpertest.py

import unittest
import odbchelper

class GoodInput(unittest.TestCase):
    def testBlank(self):
        """buildConnectionString handles empty dictionary"""
        self.assertEqual("", odbchelper.buildConnectionString({}))
    def testKnownValue(self):
        """buildConnectionString returns known result with known input"""
        params = {"server":"mpilgrim", "database":"master", "uid":"sa", "pwd":"secret"}
        knownItems = params.items()
        knownItems.sort()
        knownString = repr(knownItems)
        result = odbchelper.buildConnectionString(params)
        resultItems = [tuple(e.split("=")) for e in result.split(";")]
        resultItems.sort()
        resultString = repr(resultItems)
        self.assertEqual(knownString, resultString)

class BadInput(unittest.TestCase):
    def testString(self):
        """buildConnectionString should fail with string input"""
        self.assertRaises(AttributeError, odbchelper.buildConnectionString, "")

    def testList(self):
        """buildConnectionString should fail with list input"""
        self.assertRaises(AttributeError, odbchelper.buildConnectionString, [])

    def testTuple(self):
        """buildConnectionString should fail with tuple input"""
        self.assertRaises(AttributeError, odbchelper.buildConnectionString, ())

if __name__ == "__main__":
    unittest.main()