Subset pandas dataframe up to when condition is met the first time - python

I have not had any luck accomplishing a task, where I want to subset a pandas dataframe up to a value, and grouping by their id. In the actual dataset I have several columns in between 'id' and 'status'
For example:
d = {'id': [1,1,1,1,1,1,1,2,2,2,2,2,2,2], 'status': [0,0,0,0,1,1,1,0,0,0,0,1,0,1]}
df = pd.DataFrame(data=d)
id status
0 1 0
1 1 0
2 1 0
3 1 0
4 1 1
5 1 1
6 1 1
7 2 0
8 2 0
9 2 0
10 2 0
11 2 1
12 2 0
13 2 1
The desired subset would be:
id status
0 1 0
1 1 0
2 1 0
3 1 0
4 1 1
5 2 0
6 2 0
7 2 0
8 2 0
9 2 1

Let's try groupby + cumsum:
df = df.groupby('id', group_keys=False)\
.apply(lambda x: x[x.status.cumsum().cumsum().le(1)])\
.reset_index(drop=1)
df
id status
0 1 0
1 1 0
2 1 0
3 1 0
4 1 1
5 2 0
6 2 0
7 2 0
8 2 0
9 2 1
Here's an alternative that performs a groupby to create a mask to be used as an indexer:
df = df[df.status.eq(1).groupby(df.id)\
.apply(lambda x: x.cumsum().cumsum().le(1))]\
.reset_index(drop=1)
df
id status
0 1 0
1 1 0
2 1 0
3 1 0
4 1 1
5 2 0
6 2 0
7 2 0
8 2 0
9 2 1

Related

Add a column based on frequency for each group

I have a dataframe like this:
vehicle_id trip
0 0 0
1 0 0
2 0 0
3 0 1
4 0 1
5 1 0
6 1 0
7 1 1
8 1 1
9 1 1
10 1 1
11 1 1
12 1 2
13 2 0
14 2 1
15 2 2
I want to add a column that counts the frequency of each trip value for each 'vehicle id' group and drop the rows where the frequency is equal to 'one'. So after adding the column the frequency will be like this:
vehicle_id trip frequency
0 0 0 3
1 0 0 3
2 0 0 3
3 0 1 2
4 0 1 2
5 1 0 2
6 1 0 2
7 1 1 5
8 1 1 5
9 1 1 5
10 1 1 5
11 1 1 5
12 1 2 1
13 2 0 1
14 2 1 1
15 2 2 1
and the final result will be like this
vehicle_id trip frequency
0 0 0 3
1 0 0 3
2 0 0 3
3 0 1 2
4 0 1 2
5 1 0 2
6 1 0 2
7 1 1 5
8 1 1 5
9 1 1 5
10 1 1 5
11 1 1 5
what is the best solution for that? Also, what should I do if I intend to directly drop rows where the frequency is equal to 1 in each group (without adding the frequency column)?
Check the collab here :
https://colab.research.google.com/drive/1AuBTuW7vWj1FbJzhPuE-QoLncoF5W_7W?usp=sharing
You can use df.groupby() :
df["frequency"] = df.groupby(["vehicle_id","trip"]).transform("count")
But of course you need to create the frequency column before_hand :
df["frequency"] = 0
If I take your dataframe as example this gives :
import pandas as pd
dict = {"vehicle_id" : [0,0,0,0,0,1,1,1,1,1,1,1],
"trip" : [0,0,0,1,1,0,0,1,1,1,1,1]}
df = pd.DataFrame.from_dict(dict)
df["frequency"] = 0
df["frequency"] = df.groupby(["vehicle_id","trip"]).transform("count")
output :
Try:
df["frequency"] = (
df.assign(frequency=0).groupby(["vehicle_id", "trip"]).transform("count")
)
print(df[df.frequency > 1])
Prints:
vehicle_id trip frequency
0 0 0 3
1 0 0 3
2 0 0 3
3 0 1 2
4 0 1 2
5 1 0 2
6 1 0 2
7 1 1 5
8 1 1 5
9 1 1 5
10 1 1 5
11 1 1 5

Pandas group consecutive and label the length

I want get consecutive length labeled data
a
---
1
0
1
0
1
1
1
0
1
1
I want :
a | c
--------
1 1
0 0
1 2
1 2
0 0
1 3
1 3
1 3
0 0
1 2
1 2
then I can calculate the mean of "b" column by group "c". tried with shift and cumsum and cumcount all not work.
Use GroupBy.transform by consecutive groups and then set 0 if not 1 in a column:
df['c1'] = (df.groupby(df.a.ne(df.a.shift()).cumsum())['a']
.transform('size')
.where(df.a.eq(1), 0))
print (df)
a b c c1
0 1 1 1 1
1 0 2 0 0
2 1 3 2 2
3 1 2 2 2
4 0 1 0 0
5 1 3 3 3
6 1 1 3 3
7 1 3 3 3
8 0 2 0 0
9 1 2 2 2
10 1 1 2 2
If there are only 0, 1 values is possible multiple by a:
df['c1'] = (df.groupby(df.a.ne(df.a.shift()).cumsum())['a']
.transform('size')
.mul(df.a))
print (df)
a b c c1
0 1 1 1 1
1 0 2 0 0
2 1 3 2 2
3 1 2 2 2
4 0 1 0 0
5 1 3 3 3
6 1 1 3 3
7 1 3 3 3
8 0 2 0 0
9 1 2 2 2
10 1 1 2 2

Cumulative sum problem considering data till last record with multiple IDs

I have a dataset with multiple IDs and dates where I have created a column for Cumulative supply in python.
My data is as follows
SKU Date Demand Supply Cum_Supply
1 20160207 6 2 2
1 20160214 5 0 2
1 20160221 1 0 2
1 20160228 6 0 2
1 20160306 1 0 2
1 20160313 101 0 2
1 20160320 1 0 2
1 20160327 1 0 2
2 20160207 0 0 0
2 20160214 0 0 0
2 20160221 2 0 0
2 20160228 2 0 0
2 20160306 2 0 0
2 20160313 1 0 0
2 20160320 1 0 0
2 20160327 1 0 0
Where Cum_supply was calculated by
idx = pd.MultiIndex.from_product([np.unique(data.Date), data.SKU.unique()])
data2 = data.set_index(['Date', 'SKU']).reindex(idx).fillna(0)
data2 = pd.concat([data2, data2.groupby(level=1).cumsum().add_prefix('Cum_')],1).sort_index(level=1).reset_index()
I want to create a Column 'True_Demand' which is max unfulfilled demand till that date max(Demand-Supply) + Cum_supply.
So my output would be something this:
SKU Date Demand Supply Cum_Supply True_Demand
1 20160207 6 2 2 6
1 20160214 5 0 2 7
1 20160221 1 0 2 7
1 20160228 6 0 2 8
1 20160306 1 0 2 8
1 20160313 101 0 2 103
1 20160320 1 0 2 103
1 20160327 1 0 2 103
2 20160207 0 0 0 0
2 20160214 0 0 0 0
2 20160221 2 0 0 2
2 20160228 2 0 0 2
2 20160306 2 0 0 2
2 20160313 1 0 0 2
2 20160320 1 0 0 2
2 20160327 1 0 0 2
So for the 3rd record(20160221) the max unfulfilled demand before 20160221 was 5. So the True demand is 5+2 = 7 despite the unfulfilled demand on that date was 1+2.
Code for the dataframe
data = pd.DataFrame({'SKU':[1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2],
'Date':[20160207,20160214,20160221,20160228,20160306,20160313,20160320,20160327,20160207,20160214,20160221,20160228,20160306,20160313,20160320,20160327],
'Demand':[6,5,1,6,1,101,1,1,0,0,2,2,2,1,1,1],
'Supply':[2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}
,columns=['Date', 'SKU', 'Demand', 'Supply'])
Would you try this pretty fun one-liner?
(data.groupby('SKU',
as_index=False,
group_keys=False)
.apply(lambda x:
x.assign(Cum_Supply=x.Supply.cumsum())
.pipe(lambda x:
x.assign(True_Demand = (x.Demand - x.Supply + x.Cum_Supply).cummax()))))
Output:
Date SKU Demand Supply Cum_Supply True_Demand
0 20160207 1 6 2 2 6
1 20160214 1 5 0 2 7
2 20160221 1 1 0 2 7
3 20160228 1 6 0 2 8
4 20160306 1 1 0 2 8
5 20160313 1 101 0 2 103
6 20160320 1 1 0 2 103
7 20160327 1 1 0 2 103
8 20160207 2 0 0 0 0
9 20160214 2 0 0 0 0
10 20160221 2 2 0 0 2
11 20160228 2 2 0 0 2
12 20160306 2 2 0 0 2
13 20160313 2 1 0 0 2
14 20160320 2 1 0 0 2
15 20160327 2 1 0 0 2

alternative way to construct pivot table

>>> df = pd.DataFrame({'a': [1,1,1,1,2,2,2,2,3,3,3,3],
'b': [0,0,1,1,0,0,1,1,0,0,1,1,],
'c': [5,5,5,8,9,9,6,6,7,8,9,9]})
>>> df
a b c
0 1 0 5
1 1 0 5
2 1 1 5
3 1 1 8
4 2 0 9
5 2 0 9
6 2 1 6
7 2 1 6
8 3 0 7
9 3 0 8
10 3 1 9
11 3 1 9
Is there an alternative way to get this output?
>>> pd.pivot_table(df, index=['a','b'], columns='c', aggfunc=len, fill_value=0).reset_index()
c a b 5 6 7 8 9
0 1 0 2 0 0 0 0
1 1 1 1 0 0 1 0
2 2 0 0 0 0 0 2
3 2 1 0 2 0 0 0
4 3 0 0 0 1 1 0
5 3 1 0 0 0 0 2
I have a large df (>~1m lines) with len(df.c.unique()) being 134 so pivot is taking forever.
I was thinking that, given that this result is returned within a second in my actual df:
>>> df.groupby(by = ['a', 'b', 'c']).size().reset_index()
a b c 0
0 1 0 5 2
1 1 1 5 1
2 1 1 8 1
3 2 0 9 2
4 2 1 6 2
5 3 0 7 1
6 3 0 8 1
7 3 1 9 2
whether I could manually construct the desired outcome from this output above
1. Here's one:
df.groupby(by = ['a', 'b', 'c']).size().unstack(fill_value=0).reset_index()
Output:
c a b 5 6 7 8 9
0 1 0 2 0 0 0 0
1 1 1 1 0 0 1 0
2 2 0 0 0 0 0 2
3 2 1 0 2 0 0 0
4 3 0 0 0 1 1 0
5 3 1 0 0 0 0 2
2. Here's another way:
pd.crosstab([df.a,df.b], df.c).reset_index()
Output:
c a b 5 6 7 8 9
0 1 0 2 0 0 0 0
1 1 1 1 0 0 1 0
2 2 0 0 0 0 0 2
3 2 1 0 2 0 0 0
4 3 0 0 0 1 1 0
5 3 1 0 0 0 0 2

Pandas - updating sequence of values

I have this Sample DataFrame:
pd.DataFrame(data={1:[0,3,4,1], 2:[4,1,0,0], 3:[0,0,1,2], 4:[1,2,3,4] })
1 2 3 4
0 0 4 0 1
1 3 1 0 2
2 4 0 1 3
3 1 0 2 4
But i want to convert it to the format below:
pd.DataFrame(data={1:[1,1,1,1], 2:[0,2,0,2], 3:[0,3,3,0], 4:[4,0,4,4] })
1 2 3 4
0 1 0 0 4
1 1 2 3 0
2 1 0 3 4
3 1 2 0 4
Is there any way or a function to do this as i have more than 100,000 rows so for loops, dictionaries, lists won't work.
My entry:
data = df.reset_index().melt("index").query("value > 0")
out = data.pivot("index", "value", "value").fillna(0).astype(int)
giving
In [273]: out
Out[273]:
value 1 2 3 4
index
0 1 0 0 4
1 1 2 3 0
2 1 0 3 4
3 1 2 0 4
Unfortunately you'd have to clear the index and column names if you want to get rid of them, using either df.index.name = df.columns.name = None or df.rename_axis(None).rename_axis(None, 1) or something.
Using get_dummies:
s = pd.get_dummies(df, columns=df.columns, prefix_sep='', prefix='')
out = s.groupby(s.columns, axis=1).sum().drop('0', 1)
out.mask(out.ne(0)).fillna(dict(zip(out.columns, out.columns))).astype(int)
1 2 3 4
0 1 0 0 4
1 1 2 3 0
2 1 0 3 4
3 1 2 0 4
Using zip and np.isin
pd.DataFrame([ np.isin(y, x)*df.columns.values for x , y in zip([df.columns.values]*len(df),df.values)])
Out[900]:
0 1 2 3
0 0 2 0 4
1 1 2 0 4
2 1 0 3 4
3 1 0 3 4

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