我有一个熊猫数据帧“DT = MYFUNC()”,并从IDLE输出的屏幕拷贝如下:为什么熊猫在一种情况下会导致“ZeroDivisionError”,但在另一种情况下却不会呢?
>>> from __future__ import division
>>> dt = __get_stk_data__(['*'], frq='CQQ', from_db=False) # my function
>>> dt = dt[dt['ebt']==0][['tax','ebt']]
>>> type(dt)
<class 'pandas.core.frame.DataFrame'>
>>> dt
tax ebt
STK_ID RPT_Date
000719 20100331 0 0
20100630 0 0
20100930 0 0
20110331 0 0
002164 20080331 0 0
300155 20120331 0 0
600094 20090331 0 0
20090630 0 0
20090930 0 0
600180 20090331 0 0
600757 20110331 0 0
>>> dt['tax_rate'] = dt.tax/dt.ebt
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "D:\Python\Lib\site-packages\pandas\core\series.py", line 72, in wrapper
return Series(na_op(self.values, other.values),
File "D:\Python\Lib\site-packages\pandas\core\series.py", line 53, in na_op
result = op(x, y)
ZeroDivisionError: float division
>>>
它花费了我很多时间去弄明白为什么熊猫引发“ZeroDivisionError:浮法事业部',而熊猫都非常好,下面的示例代码:
tuples = [('000719','20100331'),('000719','20100930'),('002164','20080331')]
index = MultiIndex.from_tuples(tuples, names=['STK_ID', 'RPT_Date'])
dt =DataFrame({'tax':[0,0,0],'ebt':[0,0,0]},index=index)
dt['tax_rate'] = dt.tax/dt.ebt
>>> dt
ebt tax tax_rate
STK_ID RPT_Date
000719 20100331 0 0 NaN
20100930 0 0 NaN
002164 20080331 0 0 NaN
>>>
我希望大熊猫提供‘男’这两种情况下,为什么‘ZeroDivisionError’发生在第一种情况?如何解决它?
下面码&屏幕输出被连接以提供进一步的信息,以调试
def __by_Q__(df):
''' this function transforms the input financial report data (which
is accumulative) to qurterly data
'''
df_q1=df[df.index.map(lambda x: x[1].endswith("0331"))]
print 'before diff:\n'
print df.dtypes
df_delta = df.diff()
print '\nafter diff: \n'
print df_delta.dtypes
q1_mask = df_delta.index.map(lambda x: x[1].endswith("0331"));
df_q234 = df_delta[~q1_mask]
rst = concat([df_q1,df_q234])
rst=rst.sort_index()
return rst
画面输出:
before diff:
sales float64
discount object
net_sales float64
cogs float64
ebt float64
tax float64
after diff:
sales object
discount object
net_sales object
cogs object
ebt object
tax object
你可以检查第一个例子的dt.dtypes吗?我也无法重现这种行为。 –
'dt.dtypes'显示'税'和'ebt'是'对象'(我不知道为什么)。我能收到你的电子邮件吗?我可以将您的整个源代码和SQLite数据文件发送给您,然后您可以重现该场景。通常,程序从SQLite后端获取财务报告数据,并尝试计算财务比率... – bigbug