Python-args和** kargs

Question

我有这个全局function ：

def filterBelowThreshold(name, feature, tids, xsongs, **kwargs):
    print (name, 'PLAYLIST')
    for i, x in enumerate(feature):
        if x < value:
            track_name = sp.track(tids[i])['name']
            xsongs.append(track_name)
            print(name, ":", "{} - feature: {}".format(track_name, x))

我想在传递以下参数的class function调用它（其变量在本地声明）：

filterBelowThreshold('myname', energy, tids, xsongs, value=0.650)

在class function内部，在函数调用之前，我声明以下变量：

energy = [item 1, item2, item3, ...]

tids = []

xsongs = []

GLOBAL函数的正确语法是什么？

Answer 1

test.py

def filterBelowThreshold(name, feature, tids, xsongs, **kwargs):
    print kwargs['value']

class Test(object):
    def __init__(self):
        energy = ['item 1', 'item2', 'item3' ]
        tids = []
        xsongs = []
        filterBelowThreshold('myname', energy, tids, xsongs, value=0.650)

a = Test()

python test.py将打印0.65

您已经正确定义了，没有问题。 您面临的问题是什么？

Answer 2

如果您使用显式参数value调用函数，则不应使用**kwargs应使用常规参数：

def filterBelowThreshold(name, feature, tids, xsongs, value):
    print(name, 'PLAYLIST')
    for tid, x in zip(tids, feature):
        if x < value:
            track_name = sp.track(tid)['name']
            xsongs.append(track_name)
            print("{} : {} - feature: {}".format(name, track_name, x))

并称它为

filterBelowThreshold('myname', energy, tids, xsongs, value=0.650)

要么

filterBelowThreshold('myname', energy, tids, xsongs, 0.650)