Python 从多索引数据帧中删除不完整的季节(熊猫)
尝试将方法从应用到多索引数据帧,似乎不起作用 以数据帧为例:Python 从多索引数据帧中删除不完整的季节(熊猫),python,pandas,Python,Pandas,尝试将方法从应用到多索引数据帧,似乎不起作用 以数据帧为例: import pandas as pd import numpy as np dates = pd.date_range('20070101',periods=3200) df = pd.DataFrame(data=np.random.randint(0,100,(3200,1)), columns =list('A')) df['A'][5,6,7, 8, 9, 10, 11, 12, 13] = np.nan #add mis
import pandas as pd
import numpy as np
dates = pd.date_range('20070101',periods=3200)
df = pd.DataFrame(data=np.random.randint(0,100,(3200,1)), columns =list('A'))
df['A'][5,6,7, 8, 9, 10, 11, 12, 13] = np.nan #add missing data points
df['date'] = dates
df = df[['date','A']]
将季节函数应用于日期时间索引
def get_season(row):
if row['date'].month >= 3 and row['date'].month <= 5:
return '2'
elif row['date'].month >= 6 and row['date'].month <= 8:
return '3'
elif row['date'].month >= 9 and row['date'].month <= 11:
return '4'
else:
return '1'
创建用于索引的“年份”列
df['Year'] = df['date'].dt.year
按年份和季节划分的多指标
df = df.set_index(['Year', 'Season'], inplace=False)
统计每个季节的数据点
count = df.groupby(level=[0, 1]).count()
减少少于75天的季节
count = count.drop(count[count.A < 75].index)
使用isin函数对所有内容都显示为false,而我希望它选择“A”中有效数据超过75天的所有季节
df = df.isin(complete)
df
每个值都是假的,我不明白为什么
我希望这是足够简洁,我需要这个工作在一个多索引使用季节,所以我包括它
编辑
另一种基于多索引重新索引的方法无法从
编辑2
我也试过这个
seasons = count[count['A'] >= 75].index
df = df[df['A'].isin(seasons)]
同样,空白输出我认为您可以使用:
我觉得“雨”应该是“A”?我猜你想做这样的事
count=df[df.A>75].groupby(级别=[0,1]).count()
。这使您的天数超过75天。在此之后,我怀疑您想使用合并或加入,而不是isin。@约翰:是的,应该是“A”-很抱歉。@约翰:对不起,我想我还不够清楚。我不想计算值大于75的天数-我想计算每个季节的天数,如果每个季节的天数超过75天,我想保留它。如果每个季节少于75天,我想删除它。谢谢,这用'True'和'False'标识了正确的变量(第一个季节是'False',因为它有很多缺失值)。但是当我使用print idx[df]
应用它时,它只返回整个数据帧,并且没有忽略少于75天的季节。嗯,如果我print df
它有3200行,如果print df[idx]
它有3106行。因此,我认为删除了94行。但我不知道怎样才能更好地检查它。你觉得怎么样?对不起,我没有重新启动内核,其中一个变量出现了故障,这确实有效,谢谢!
df = df.isin(complete)
df
df3 = df.reset_index().groupby('Year').apply(lambda x: x.set_index('Season').reindex(count,method='pad'))
seasons = count[count['A'] >= 75].index
df = df[df['A'].isin(seasons)]
complete = count[count['A'] >= 75].index
idx = df.index.isin(complete)
print idx
[ True True True ..., False False False]
print df[idx]
date A
Year Season
2007 1 2007-01-01 24.0
1 2007-01-02 92.0
1 2007-01-03 54.0
1 2007-01-04 91.0
1 2007-01-05 91.0
1 2007-01-06 NaN
1 2007-01-07 NaN
1 2007-01-08 NaN
1 2007-01-09 NaN
1 2007-01-10 NaN
1 2007-01-11 NaN
1 2007-01-12 NaN
1 2007-01-13 NaN
1 2007-01-14 NaN
1 2007-01-15 18.0
1 2007-01-16 82.0
1 2007-01-17 55.0
1 2007-01-18 64.0
1 2007-01-19 89.0
1 2007-01-20 37.0
1 2007-01-21 45.0
1 2007-01-22 4.0
1 2007-01-23 34.0
1 2007-01-24 35.0
1 2007-01-25 90.0
1 2007-01-26 17.0
1 2007-01-27 29.0
1 2007-01-28 58.0
1 2007-01-29 7.0
1 2007-01-30 57.0
... ... ...
2015 3 2015-08-02 42.0
3 2015-08-03 0.0
3 2015-08-04 31.0
3 2015-08-05 39.0
3 2015-08-06 25.0
3 2015-08-07 1.0
3 2015-08-08 7.0
3 2015-08-09 97.0
3 2015-08-10 38.0
3 2015-08-11 59.0
3 2015-08-12 28.0
3 2015-08-13 84.0
3 2015-08-14 43.0
3 2015-08-15 63.0
3 2015-08-16 68.0
3 2015-08-17 0.0
3 2015-08-18 19.0
3 2015-08-19 61.0
3 2015-08-20 11.0
3 2015-08-21 84.0
3 2015-08-22 75.0
3 2015-08-23 37.0
3 2015-08-24 40.0
3 2015-08-25 66.0
3 2015-08-26 50.0
3 2015-08-27 74.0
3 2015-08-28 37.0
3 2015-08-29 19.0
3 2015-08-30 25.0
3 2015-08-31 15.0
[3106 rows x 2 columns]