I hope with these additional information someone could find time to help me with this new issue.
sample date here --> file
'Date as index' (datetime.date)
As I said I'm trying to select a range in a dataframe every time x is in interval [-20 -190] and create a new dataframe with a new column which is the sum of the selected rows and keep the last "encountered" date as index
EDIT : The "loop" start at the first date/beginning of the df and when a value which is less than 0 or -190 is found, then sum it up and continue to find and sum it up and so on
BUT I still got values which are still in the intervall (-190, 0)
example and code below.
Thks
import pandas as pd
df = pd.read_csv('http://www.sharecsv.com/s/0525f76a07fca54717f7962d58cac692/sample_file.csv', sep = ';')
df['Date'] = df['Date'].where(df['x'].between(-190, 0)).bfill()
df3 = df.groupby('Date', as_index=False)['x'].sum()
df3
##### output #####
Date sum
0 2019-01-01 13:48:00 -131395.21
1 2019-01-02 11:23:00 -250830.08
2 2019-01-02 11:28:00 -154.35
3 2019-01-02 12:08:00 -4706.87
4 2019-01-03 12:03:00 -260158.22
... ... ...
831 2019-09-29 09:18:00 -245939.92
832 2019-09-29 16:58:00 -0.38
833 2019-09-30 17:08:00 -129365.71
834 2019-09-30 17:13:00 -157.05
835 2019-10-01 08:58:00 -111911.98
########## expected output #############
Date sum
0 2019-01-01 13:48:00 -131395.21
1 2019-01-02 11:23:00 -250830.08
2 2019-01-02 12:08:00 -4706.87
3 2019-01-03 12:03:00 -260158.22
... ... ...
831 2019-09-29 09:18:00 -245939.92
832 2019-09-30 17:08:00 -129365.71
833 2019-10-01 08:58:00 -111911.98
...
...
Use Series.where with Series.between for replace values to NaNs of Date column with back filling missing values and then aggregate sum, next step is filter out rows with match range by boolean indexing and last use DataFrame.resample with cast Series to one column DataFrame by Series.to_frame:
#range -190, 0
df['Date'] = df['Date'].where(df['x'].between(-190, 0)).bfill()
df3 = df.groupby('Date', as_index=False)['x'].sum()
df3 = df3[~df3['x'].between(-190, 0)]
df3 = df3.resample('D', on='Date')['x'].sum().to_frame()
Related
I have a df like this:
df = pd.DataFrame({'a': ['2019-09-01 17:00:00', '2019-09-01 17:15:00','2019-09-01 17:30:00','2019-09-01 17:45:00','2019-09-01 18:00:00', '2019-09-01 18:15:00','2019-09-01 18:30:00','2019-09-01 18:45:00'],
'b': [432.6, 427.56, 424.2, 433.44,450.24,447.72,452.76,453.6]})
And I want to create a loop to calculate the mean of the values for every 4 items like this:
When i = 0 (first position)
mean0 = df.loc[0:3,'b'].mean()
When i = 1:
mean1 = df.loc[4:7,'b'].mean()
And so on.I've tried to create something like this:
for i in df['b]:
mean[i] = (df[i,'b'] + df.loc[(i+1),'b'] + df.loc[(i+2),'b'])+df.loc[(i+3),'b'])).mean()
But i always get a error message KeyError: 655.7077670000001 or Nan values.
Thanks for the help.
Try this:
>>> df.groupby(df.index // 4).mean()
b
0 429.45
1 451.08
Or maybe
>>> df['mean'] = df.groupby(df.index // 4)['b'].transform('mean')
>>> df
a b mean
0 2019-09-01 17:00:00 432.60 429.45
1 2019-09-01 17:15:00 427.56 429.45
2 2019-09-01 17:30:00 424.20 429.45
3 2019-09-01 17:45:00 433.44 429.45
4 2019-09-01 18:00:00 450.24 451.08
5 2019-09-01 18:15:00 447.72 451.08
6 2019-09-01 18:30:00 452.76 451.08
7 2019-09-01 18:45:00 453.60 451.08
This solution is efficient as it is vectorized
mean=list(df.groupby(df.index//4)['b'].mean())
And if you want to continue doing your own method for exploring here is the code
n=df.shape[0]//4
mean=[0]*n
for i in range(n):
mean[i] = (df.loc[i*4,'b'] + df.loc[(i*4+1),'b'] + df.loc[(i*4+2),'b']+df.loc[(i*4+3),'b'])/4
Output:
[429.45000000000005, 451.08000000000004]
your code was giving you error because .loc was missing here df[i,'b']=>df.loc[i*4,'b']
Maybe you want to group every 4 values because you want to resample your dataframe.
Try:
out = df.groupby(pd.to_datetime(df['a']).dt.floor('H')).mean().reset_index()
print(out)
# Output
a b
0 2019-09-01 17:00:00 429.45
1 2019-09-01 18:00:00 451.08
I have tried a few answers but was not able to get the desired result in my case.
I am working with stocks data.
I have a list ['3MINDIA.NS.csv', 'AARTIDRUGS.NS.csv', 'AARTIIND.NS.csv', 'AAVAS.NS.csv', 'ABB.NS.csv']
for every stock in the list I get an output which contains trades and related info.. it looks something like this:
BUY SELL profits rel_profits
0 2004-01-13 2004-01-27 -44.200012 -0.094606
1 2004-02-05 2004-02-16 18.000000 0.044776
2 2005-03-08 2005-03-11 25.000000 0.048077
3 2005-03-31 2005-04-01 13.000000 0.025641
4 2005-10-11 2005-10-26 -20.400024 -0.025342
5 2005-10-31 2005-11-04 67.000000 0.095578
6 2006-05-22 2006-06-05 -55.100098 -0.046693
7 2007-03-06 2007-03-14 3.000000 0.001884
8 2007-03-19 2007-03-28 41.500000 0.028222
9 2007-07-31 2007-08-14 69.949951 0.038224
10 2008-01-24 2008-02-05 25.000000 0.013055
11 2009-11-04 2009-11-05 50.000000 0.031250
12 2010-12-10 2010-12-15 63.949951 0.018612
13 2011-02-02 2011-02-15 -53.050049 -0.015543
14 2011-09-30 2011-10-07 74.799805 0.018181
15 2015-12-09 2015-12-18 -215.049805 -0.019523
16 2016-01-18 2016-02-01 -475.000000 -0.046005
17 2016-11-16 2016-11-30 -1217.500000 -0.096877
18 2018-03-26 2018-04-02 0.250000 0.000013
19 2018-05-22 2018-05-25 250.000000 0.012626
20 2018-06-05 2018-06-12 101.849609 0.005361
21 2018-09-25 2018-10-10 -2150.000000 -0.090717
22 2021-01-27 2021-02-03 500.150391 0.024638
23 2021-06-30 2021-07-07 393.000000 0.016038
24 2021-08-12 2021-08-13 840.000000 0.035279
25 NaN NaN -1693.850281 0.995277
# note: every dataframe will have a last row with NaN values in buy, sell columns
# each datafram has different number of rows
Now I tried to add an extra level of index to this dataframe like this:
symbol = name of the stock from given list for ex. for 3MINDIA.NS.csv symbol is 3MINDIA
trades.columns = pd.MultiIndex.from_product([[symbol], trades.columns])
after this I tried to concatenate each trades dataframe that is generated in the loop to a main dataframe using:
result_df = pd.concat([result_df, trades], axis=1)
# I am trying to do this so that Whenever
I call result_df[symbol] I should be able
to see the trade dates for that particular symbol.
But I get a result_df that has lot of NaN values because each trades dataframe has variable number of rows in it.
IS there any way I can combine trades dataframes along the columns with stock symbol as higher level index and not get all the NaN values in my result_df
result_df I got
So I found a way to get what I wanted.
first I added this code in loop
trades = pd.concat([trades], keys=[symbol], names=['Stocks'])
after this I used concatenate again on result_df and trades
# Desired Result
result_df = pd.concat([result_df, trades], axis=0, ignore_index=False)
And BAM!!! This is exactly what I wanted
I have a data frame with two date columns, a start and end date. How will I find the number of weekends between the start and end dates using pandas or python date-times
I know that pandas has DatetimeIndex which returns values 0 to 6 for each day of the week, starting Monday
# create a data-frame
import pandas as pd
df = pd.DataFrame({'start_date':['4/5/19','4/5/19','1/5/19','28/4/19'],
'end_date': ['4/5/19','5/5/19','4/5/19','5/5/19']})
# convert objects to datetime format
df['start_date'] = pd.to_datetime(df['start_date'], dayfirst=True)
df['end_date'] = pd.to_datetime(df['end_date'], dayfirst=True)
# Trying to get the date index between dates as a prelim step but fails
pd.DatetimeIndex(df['end_date'] - df['start_date']).weekday
I'm expecting the result to be this: (weekend_count includes both start and end dates)
start_date end_date weekend_count
4/5/2019 4/5/2019 1
4/5/2019 5/5/2019 2
1/5/2019 4/5/2019 1
28/4/2019 5/5/2019 3
IIUC
df['New']=[pd.date_range(x,y).weekday.isin([5,6]).sum() for x , y in zip(df.start_date,df.end_date)]
df
start_date end_date New
0 2019-05-04 2019-05-04 1
1 2019-05-04 2019-05-05 2
2 2019-05-01 2019-05-04 1
3 2019-04-28 2019-05-05 3
Try with:
df['weekend_count']=((df.end_date-df.start_date).dt.days+1)-np.busday_count(
df.start_date.dt.date,df.end_date.dt.date)
print(df)
start_date end_date weekend_count
0 2019-05-04 2019-05-04 1
1 2019-05-04 2019-05-05 2
2 2019-05-01 2019-05-04 1
3 2019-04-28 2019-05-05 3
I have this regular dataframe indexed by 'Date', called ES:
Price Day Hour num_obs med abs_med Ret
Date
2006-01-03 08:30:00 1260.583333 1 8 199 1260.416667 0.166667 0.000364
2006-01-03 08:35:00 1261.291667 1 8 199 1260.697917 0.593750 0.000562
2006-01-03 08:40:00 1261.125000 1 8 199 1260.843750 0.281250 -0.000132
2006-01-03 08:45:00 1260.958333 1 8 199 1260.895833 0.062500 -0.000132
2006-01-03 08:50:00 1261.214286 1 8 199 1260.937500 0.276786 0.000203
I have this other dataframe indexed by the following MultiIndex. The first index goes from 0 to 23 and the second index goes from 0 to 55. In other words we have daily 5 minute increment data.
5min_Ret
0 0 2.235875e-06
5 9.814064e-07
10 -1.453213e-06
15 4.295757e-06
20 5.884896e-07
25 -1.340122e-06
30 9.470660e-06
35 1.178204e-06
40 -1.111621e-05
45 1.159005e-05
50 6.148861e-06
55 1.070586e-05
1 0 1.485287e-05
5 3.018576e-06
10 -1.513273e-05
15 -1.105312e-05
20 3.600874e-06
...
I want to create a column in the original dataframe, ES, that has the appropriate '5min_Ret' at each appropriate hour/5minute combo.
I've tried multiple things: looping over rows, finding some apply function. But nothing has worked so far. I feel like I'm overlooking a simple and Pythonic solution here.
The expected output creates a new column called '5min_ret' to the original dataframe in which each row corresponds to the correct hour/5minute pair from the smaller dataframe containing the 5min_ret
Price Day Hour num_obs med abs_med Ret 5min_ret
Date
2006-01-03 08:30:00 1260.583333 1 8 199 1260.416667 0.166667 0.000364 xxxx
2006-01-03 08:35:00 1261.291667 1 8 199 1260.697917 0.593750 0.000562 xxxx
2006-01-03 08:40:00 1261.125000 1 8 199 1260.843750 0.281250 -0.000132 xxxx
2006-01-03 08:45:00 1260.958333 1 8 199 1260.895833 0.062500 -0.000132 xxxx
2006-01-03 08:50:00 1261.214286 1 8 199 1260.937500 0.276786 0.000203 xxxx
I think one way is to use merge on hour and minute. First create a column 'min' in ES from the datetimeindex such as:
ES['min'] = ES.index.minute
Now you can merge with your multiindex DF containing the column '5min_Ret' that I named df_multi such as:
ES = ES.merge(df_multi.reset_index(), left_on = ['hour','min'],
right_on = ['level_0','level_1'], how='left')
Here you merge on 'hour' and 'min' from ES with 'level_0' and 'level_1', which are created from your multiindex of df_multi when you do reset_index, and on the value of the left df (being ES)
You should get a new column in ES named '5min_Ret' with the value you are looking for. You can drop the colum 'min' if you don't need it anymore by ES = ES.drop('min',axis=1)
I'm trying to get top5 values for amount for each month along with the text column. I've tried resampling and group by statement
Dataset:
text amount date
123… 11.00 11-05-17
123abc… 10.00 11-08-17
Xyzzy… 22.00. 12-07-17
Xyzzy… 221.00. 11-08-17
Xyzzy… 212.00. 10-08-17
Xyzzy… 242.00. 18-08-17
Code:
df1 = df.groupby([’text', pd.Grouper(key=‘date', freq='M')])[‘amount'].apply(lambda x: x.nlargest(5))
I get group of text but not arranged by month or largest values sorted in descending order.
df1 = df.groupby([pd.Grouper(key=‘date', freq='M')])[‘amount'].apply(lambda x: x.nlargest(5))
THis code works fine but does not give text column.
assuming that amount is a numeric column:
In [8]: df.groupby(['text', pd.Grouper(key='date', freq='M')]).apply(lambda x: x.nlargest(2, 'amount'))
Out[8]:
text amount date
text date
123abc… 2017-11-30 1 123abc… 10.0 2017-11-08
123… 2017-11-30 0 123… 11.0 2017-11-05
Xyzzy… 2017-08-31 5 Xyzzy… 242.0 2017-08-18
2017-10-31 4 Xyzzy… 212.0 2017-10-08
2017-11-30 3 Xyzzy… 221.0 2017-11-08
2017-12-31 2 Xyzzy… 22.0 2017-12-07
You can using head with sort_values
df1 = df.sort_values('amount',ascending=False).groupby(['text', pd.Grouper(key='date', freq='M')]).head(2)