我试图计算一个条件正在发生的次数。
我读到了groupby.cumcount()
,但它并没有按照我想要的方式运作。
以下是数据的一小部分:
min max
time
1970-01-02 -3.440000 -1.180000
1970-01-03 -4.830000 -0.700000
1970-01-04 -6.250000 0.250000
1970-01-05 -11.700000 -6.690000
1970-01-06 -13.000000 -3.720000
1970-01-07 -3.870000 2.070000
1970-01-08 0.320000 2.690000
1970-01-09 -5.170000 2.310000
1970-01-10 -4.540000 1.140000
1970-01-11 -7.260000 1.300000
1970-01-12 -9.870000 -0.780000
1970-01-13 -6.520000 -0.390000
1970-01-14 -8.490000 -5.090000
1970-01-15 -13.670000 -8.670000
1970-01-16 -11.080000 -4.110000
1970-01-17 -24.770000 -7.320000
1970-01-18 -29.709999 -24.230000
1970-01-19 -24.200001 -19.480000
1970-01-20 -31.000000 -13.810000
1970-01-21 -36.389999 -30.209999
1970-01-22 -39.889999 -36.990002
1970-01-23 -41.750000 -38.730000
1970-01-24 -38.259998 -8.510000
1970-01-25 -14.100000 -5.740000
1970-01-26 -12.000000 -8.540000
1970-01-27 -12.060000 -7.470000
1970-01-28 -10.230000 -7.710000
1970-01-29 -10.850000 -8.400000
1970-01-30 -15.270000 -9.870000
1970-01-31 -11.920000 -5.290000
考虑条件:df['min'] <= -30
以及 3天的优势或期限。
我想知道我们有多少次连续三天以'-30'的年龄低于-30岁。
所以结果就像(虚拟值):
occurences
time
1970 3
1971 4
1972 2
1973 3
我玩过一些解决方案,但我无法接近,有什么建议吗?
答案 0 :(得分:3)
IIUC:
In [94]: x = df[df.rolling(3)['min'].max() <= -30]
In [95]: x.groupby(x.index.year)['min'].count().to_frame('occurences')
Out[95]:
occurences
1970 3