在python中使用多线程时：为什么它没有表现出更好的时间？

Question

我在python中编写了以下代码，以便处理多线程并允许并行运行各种方法。至少这是我所希望的

import threading
import time

class FuncThread(threading.Thread):
    results = None

    def __init__(self, target, *args):
        threading.Thread.__init__(self)
        self._target = target
        self._args = args 


    def run(self):
        assert( self._target!= None )
        self.results = self._target(*self._args[0])


def run_all(func):

    threads = []

    for i in range(len(func)):
        f = func[i]
        param = f[1:]
        f = f[0]
        if param != None:
            t = FuncThread(f, param)
        else:
            t = FuncThread(f)

        t.start()
        threads.append(t)

    # Wait for all threads to complete
    #print ('********** waiting for threads to complete')
    results = []
    for t in threads:
        t.join()
    for t in threads:
        results.append(t.results)
        #print ('Finished: ' + str(t.results))
    #print ('********** threads are done')
    return results

我写了以下测试以测量时间但是我没有看到任何改进次数！

if __name__ == '__main__':
    def func1(data, key):
        #print ("data={0}; key={1}".format(str(data), str(key)))
        c = 0
        for i in range(50000):
            c += data

        return c

    def func2(data, key):
        #print ("data={0}; key={1}".format(str(data), str(key)))
        c = 1
        m = 1
        for i in range(50000):
            m *= c
            c += 1
            #print(c, key)

        return c,m

    print('\nregular call:\n')
    base = time.time()
    for i in range(10):
        func1(34, 2)
        func2(3, 2)

    print('spent: ' + str(time.time() - base) + ' seconds')
    print('\nnow let\'s try with threads:\n')

    base = time.time()
    for i in range(10):
        run_all([ (func1, 34, 2) , [func2, 3, 2] ] )

    print('spent: ' + str(time.time() - base) + ' seconds')

使用多线程时，结果没有显示任何时间的改善，相反，它显示出一些回归和缓慢

    regular call:
    spent: 12.752724409103394 seconds

    now let's try with threads:
    spent: 13.019697904586792 seconds

我做错了什么？