records = {'foo':foo, 'bar':bar, 'baz':baz}
如果值为0
,我想将值更改为None
。我怎么能这样做?
例如:
records = {'foo':None, 'bar':None, 'baz':1}
我想将foo
和bar
更改为0
。
最后的决定:
records = {'foo':0, 'bar':0, 'baz':1}
答案 0 :(得分:19)
for k in records:
if records[k] is None:
records[k] = 0
答案 1 :(得分:19)
另一种方式
records.update((k, 0) for k,v in records.iteritems() if v is None)
实施例
>>> records
{'bar': None, 'baz': 1, 'foo': None}
>>> records.update((k, 0) for k,v in records.iteritems() if v is None)
>>> records
{'bar': 0, 'baz': 1, 'foo': 0}
答案 2 :(得分:13)
尝试
for key, value in records.iteritems():
if value is None:
records[key] = 0
答案 3 :(得分:9)
for k, v in records.items():
if v is None:
records[k] = 0
答案 4 :(得分:2)
如果你想恐吓或惹恼其他代码维护者,那么就会有一个丑陋的单行代码可以解决这个问题:
records.update(map(lambda (k,v):(k,{v:v,None:0}[v]), records.items()))
使用示例:
>>> records = {"hey":None, "you":0}
>>> records.update(map(lambda (k,v):(k,{v:v,None:0}[v]), records.items()))
>>> records
{'you': 0, 'hey': 0}
答案 5 :(得分:0)
records = dict( ( k,0 if v is None else v ) for k, v in records.items() )
def zero_if_none( x ):
return 0 if x is None else x
records = dict( ( k, zero_if_none( records[k] ) ) for k in records )