I am trying to create a "total" column in my dataframe
idx = pd.MultiIndex.from_product([['Room 1','Room 2', 'Room 3'],['on','off']])
df = pd.DataFrame([[1,4,3,6,5,15], [3,2,1,5,1,7]], columns=idx)
My dataframe
Room 1 Room 2 Room 3
on off on off on off
0 1 4 3 6 5 15
1 3 2 1 5 1 7
For each room, I want to create a total column and then a on% column.
I have tried the following, however, it does not work.
df.loc[:, slice(None), "total" ] = df.xs('on', axis=1,level=1) + df.xs('off', axis=1,level=1)
Let us try something fancy ~
df.stack(0).eval('total=on + off \n on_pct=on / total').stack().unstack([1, 2])
Room 1 Room 2 Room 3
off on total on_pct off on total on_pct off on total on_pct
0 4.0 1.0 5.0 0.2 6.0 3.0 9.0 0.333333 15.0 5.0 20.0 0.250
1 2.0 3.0 5.0 0.6 5.0 1.0 6.0 0.166667 7.0 1.0 8.0 0.125
Oof this was a roughie, but you can do it like this if you want to avoid loops. Worth noting it redefines your df twice because i need the total columns. Sorry about that, but is the best i could do. Also if you have any questions just comment.
df = pd.concat([y.assign(**{'Total {0}'.format(x+1): y.iloc[:,0] + y.iloc[:,1]})for x , y in df.groupby(np.arange(df.shape[1])//2,axis=1)],axis=1)
df = pd.concat([y.assign(**{'Percentage_Total{0}'.format(x+1): (y.iloc[:,0] / y.iloc[:,2])*100})for x , y in df.groupby(np.arange(df.shape[1])//3,axis=1)],axis=1)
print(df)
This groups by the column's first index (rooms) and then loops through each group to add the total and percent on. The final step is to reindex using the unique rooms:
import pandas as pd
idx = pd.MultiIndex.from_product([['Room 1','Room 2', 'Room 3'],['on','off']])
df = pd.DataFrame([[1,4,3,6,5,15], [3,2,1,5,1,7]], columns=idx)
for room, group in df.groupby(level=0, axis=1):
df[(room, 'total')] = group.sum(axis=1)
df[(room, 'pct_on')] = group[(room, 'on')] / df[(room, 'total')]
result = df.reindex(columns=df.columns.get_level_values(0).unique(), level=0)
Output:
Room 1 Room 2 Room 3
on off total pct_on on off total pct_on on off total pct_on
0 1 4 5 0.2 3 6 9 0.333333 5 15 20 0.250
1 3 2 5 0.6 1 5 6 0.166667 1 7 8 0.125
Related
I have a df which looks like the below, There are 2 quantity columns and I want to move the quantities in the "QTY 2" column to the "QTY" column
Note: there are no instances where there are values in the same row for both columns (So for each row, QTY is either populated or else QTY 2 is populated. Not Both)
DF
Index
Product
QTY
QTY 2
0
Shoes
5
1
Jumpers
10
2
T Shirts
15
3
Shorts
13
Desired Output
Index
Product
QTY
0
Shoes
5
1
Jumpers
10
2
T Shirts
15
3
Shorts
13
Thanks
Try this:
import numpy as np
df['QTY'] = np.where(df['QTY'].isnull(), df['QTY 2'], df['QTY'])
df["QTY"] = df["QTY"].fillna(df["QTY 2"], downcast="infer")
filling the gaps of QTY with QTY 2:
In [254]: df
Out[254]:
Index Product QTY QTY 2
0 0 Shoes 5.0 NaN
1 1 Jumpers NaN 10.0
2 2 T Shirts NaN 15.0
3 3 Shorts 13.0 NaN
In [255]: df["QTY"] = df["QTY"].fillna(df["QTY 2"], downcast="infer")
In [256]: df
Out[256]:
Index Product QTY QTY 2
0 0 Shoes 5 NaN
1 1 Jumpers 10 10.0
2 2 T Shirts 15 15.0
3 3 Shorts 13 NaN
downcast="infer" makes it "these look like integer after NaNs gone, so make the type integer".
you can drop QTY 2 after this with df = df.drop(columns="QTY 2"). If you want one-line is as usual possible:
df = (df.assign(QTY=df["QTY"].fillna(df["QTY 2"], downcast="infer"))
.drop(columns="QTY 2"))
You can do ( I am assuming your empty values are empty strings):
df = df.assign(QTY= df[['QTY', 'QTY2']].
replace('', 0).
sum(axis=1)).drop('QTY2', axis=1)
print(df):
Product QTY
0 Shoes 5
1 Jumpers 10
2 T Shirts 15
3 Shorts 13
If the empty values are actually NaNs then
df['QTY'] = df['QTY'].fillna(df['QTY2']) #or
df['QTY'] = df[['QTY', 'QTY2']].sum(1)
I have a pandas dataframe with some very extreme value - more than 5 std.
I want to replace, per column, each value that is more than 5 std with the max other value.
For example,
df = A B
1 2
1 6
2 8
1 115
191 1
Will become:
df = A B
1 2
1 6
2 8
1 8
2 1
What is the best way to do it without a for loop over the columns?
s=df.mask((df-df.apply(lambda x: x.std() )).gt(5))#mask where condition applies
s=s.assign(A=s.A.fillna(s.A.max()),B=s.B.fillna(s.B.max())).sort_index(axis = 0)#fill with max per column and resort frame
A B
0 1.0 2.0
1 1.0 6.0
2 2.0 8.0
3 1.0 8.0
4 2.0 1.0
Per the discussion in the comments you need to decide what your threshold is. say it is q=100, then you can do
q = 100
df.loc[df['A'] > q,'A'] = max(df.loc[df['A'] < q,'A'] )
df
this fixes column A:
A B
0 1 2
1 1 6
2 2 8
3 1 115
4 2 1
do the same for B
Calculate a column-wise z-score (if you deem something an outlier if it lies outside a given number of standard deviations of the column) and then calculate a boolean mask of values outside your desired range
def calc_zscore(col):
return (col - col.mean()) / col.std()
zscores = df.apply(calc_zscore, axis=0)
outlier_mask = zscores > 5
After that it's up to you to fill the values marked with the boolean mask.
df[outlier_mask] = something
df = pd.DataFrame({'Category': ['A','B','B','B','C','C'],
'Subcategory': ['X','X','Y','Y','Z','Z'],
'Values': [1,2,3,4,5,6]})
which I use groupby to summarize -
`df.groupby('Category')['Values'].agg({np.size, np.mean, np.median})`
size mean median
Category
A 1 1.0 1.0
B 3 3.0 3.0
C 2 5.5 5.5
Objective: In addition to the above, show additional groupby by subcategory 'X' to create below output:
ALL Subcategory Only Subcategory 'X'
size mean median size mean median
Category
A 1 1.0 1.0 1 1 1
B 3 3.0 3.0 1 2 2
C 2 5.5 5.5 0 0 0
My solution currently is to create two groupby, to_frame() then pd.merge them. Is there a better way? Thanks!
df.groupby('Category')['Values'].agg({np.size, np.mean, np.median})
df[df['Subcategory']=='X'].groupby('Category')['Values'].agg({np.size, np.mean, np.median})
I have the following data:
inputdata = [[1,'long',30.2,'Win'],[1,'long',-12.4,'Loss'],
[2,'short',-12.3,'Loss'],[1,'long',3.2,'Win'],
[3,'short',0.0,'B/E'],[3,'short',23.2,'Win'],
[3,'long',3.2,'Win'],[4,'short',-4.2,'Loss']]
datadf = DataFrame(columns=['AssetId','Direction','PnL','W_L'], data = inputdata)
datadf
AssetId Direction PnL W_L
0 1 long 30.2 Win
1 1 long -12.4 Loss
2 2 short -12.3 Loss
3 1 long 3.2 Win
4 3 short 0.0 B/E
5 3 short 23.2 Win
6 3 long 3.2 Win
7 4 short -4.2 Loss
Now I want to aggregate this further into a new dataframe that looks like this mock up (a few sample rows added, more stats to be added:
Stat Long Short Total
0 Trades 4 4 8
1 Won 3 1 4
2 Lost 1 2 3
(...)
I tried this:
datadf.groupby(['Direction'])['PnL'].count()
Direction
long 4
short 4
Name: PnL, dtype: int64
This produces the necessary data, but I would have to fill my aggregation data frame field by field, which seems cumbersome and I am not even sure how to get the exact value into each row/column. Based on this example, is there a better way to achieve this goal?
You can do crosstab:
pd.crosstab(df['W_L'], df['Direction'],margins=True, margins_name='Total')
Output:
Direction long short Total
W_L
B/E 0 1 1
Loss 1 2 3
Win 3 1 4
Total 4 4 8
Use pivot_table:
res = pd.pivot_table(df.iloc[:,1:], index=["W_L"], columns=["Direction"], aggfunc="count").droplevel(0, 1)
res["total"] = res.sum(1)
print (res.append(res.sum().rename(index="Trades")))
Direction long short total
W_L
B/E NaN 1.0 1.0
Loss 1.0 2.0 3.0
Win 3.0 1.0 4.0
Trades 4.0 4.0 8.0
For an example:
data = {'Platoon': ['A','A','A','A','A','A','B','B','B','B','B','C','C','C','C','C'],
'Date' : [1,2,3,4,5,6,1,2,3,4,5,1,2,3,4,5],
'Casualties': [1,4,5,7,5,5,6,1,4,5,6,7,4,6,4,6]}
df = pd.DataFrame(data)
This works to calculate the rolling average, inclusive of the current row:
df['avg'] = df.groupby(['Platoon'])['Casualties'].transform(lambda x: x.rolling(2, 1).mean())
Which gives:
Platoon Date Casualties Avg
A 1 1 1.0
A 2 4 2.5
A 3 5 4.5
A 4 7 6.0
......
What I want to get is:
Platoon Date Casualties Avg
A 1 1 1.0
A 2 4 1.0
A 3 5 2.5
A 4 7 4.5
......
I suspect I can use shift here but I can't figure it out!
You need shift with bfill
df.groupby(['Platoon'])['Casualties'].apply(lambda x: x.rolling(2, 1).mean().shift().bfill())