convert specific rows of pandas dataframe into multiindex - python

here is my DataFrame:
0 1 2
0 0 0.0 20.0 NaN
1 1.0 21.0 NaN
2 2.0 22.0 NaN
ID NaN NaN 11111.0
Year NaN NaN 2011.0
1 0 3.0 23.0 NaN
1 4.0 24.0 NaN
2 5.0 25.0 NaN
3 6.0 26.0 NaN
ID NaN NaN 11111.0
Year NaN NaN 2012.0
i want to convert the 'ID' and 'Year' rows to dataframe Index with 'ID' being level=0 and 'Year' being level=1. I tried using stack() but still cannot figure it .
Edited: my desired output should look like below:
0 1
11111 2011 0 0.0 20.0
1 1.0 21.0
2 2.0 22.0
2012 0 3.0 23.0
1 4.0 24.0
2 5.0 25.0
3 6.0 26.0

This should work:
df1 = df.loc[pd.IndexSlice[:, ['ID', 'Year']], '2']
dfs = df1.unstack()
dfi = df1.index
dfn = df.drop(dfi).drop('2', axis=1).unstack()
dfn.set_index([dfs.ID, dfs.Year]).stack()

Related

Panda- How can some column values can be moved to new column?

I have the below data frame
d = {
"name":["RRR","RRR","RRR","RRR","RRR","ZZZ","ZZZ","ZZZ","ZZZ","ZZZ"],
"id":[1,1,2,2,3,2,3,3,4,4],"value":[12,13,1,44,22,21,23,53,64,9]
}
I want the out output as below:
First pivot by DataFrame.set_index with counter by GroupBy.cumcount and DataFrame.unstack with helper column ind by id, then sorting second level of MultiIndex with flatten values:
df = (df.assign(ind = df['id'])
.set_index(['name','id', df.groupby(['name','id']).cumcount()])[['value', 'ind']]
.unstack(1)
.sort_index(axis=1, kind='mergesort', level=1))
df.columns = [f'{a}_{b}' for a, b in df.columns]
df = df.droplevel(1).reset_index()
print (df)
name ind_1 value_1 ind_2 value_2 ind_3 value_3 ind_4 value_4
0 RRR 1.0 12.0 2.0 1.0 3.0 22.0 NaN NaN
1 RRR 1.0 13.0 2.0 44.0 NaN NaN NaN NaN
2 ZZZ NaN NaN 2.0 21.0 3.0 23.0 4.0 64.0
3 ZZZ NaN NaN NaN NaN 3.0 53.0 4.0 9.0
try this:
def func(sub: pd.DataFrame) ->pd.DataFrame:
dfs = [g.reset_index(drop=True).rename(
columns=lambda x: f'{x}_{n}') for n, g in sub.drop(columns='name').groupby('id')]
return pd.concat(dfs, axis=1)
res = df.groupby('name').apply(func).droplevel(1).reset_index()
print(res)
>>>
name id_1 value_1 id_2 value_2 id_3 value_3 id_4 value_4
0 RRR 1.0 12.0 2.0 1.0 3.0 22.0 NaN NaN
1 RRR 1.0 13.0 2.0 44.0 NaN NaN NaN NaN
2 ZZZ NaN NaN 2.0 21.0 3.0 23.0 4.0 64.0
3 ZZZ NaN NaN NaN NaN 3.0 53.0 4.0 9.0

How to join two dataframe with same category?

Now, I have two dataframe. I have use groupby. and count() function to export this dataframe(df1). When I used groupby. to count the total number of each category. It filtered out the category which the count is 0. How can I use Python to get the outcome?
However,I will like to have a dataframe which also required categories.
Original dataframe:
Cat UR3 VR1 VR VR3
0 ATIDS 137.0 99.0 40.0 84.0
1 BasicCrane 2.0 8.0 3.0 1.0
2 Beam Sensor 27.0 12.0 13.0 14.0
3 CLPS 1.0 NaN NaN 1.0
However,I will like to have a dataframe which also required categories.
(required categories: ATIDS, BasicCrane, LLP, Beam Sensor, CLPS, SPR)
Expected dataframe (The count number of 'LLP' and 'SPR' is 0)
Cat UR3 VR1 VR VR3
0 ATIDS 137.0 99.0 40.0 84.0
1 BasicCrane 2.0 8.0 3.0 1.0
2 LLP NaN NaN NaN NaN
3 Beam Sensor 27.0 12.0 13.0 14.0
4 CLPS 1.0 NaN NaN 1.0
5 SPR NaN NaN NaN NaN
>>> categories
['ATIDS', 'BasicCrane', 'LLP', 'Beam Sensor', 'CLPS', 'SPR']
>>> pd.merge(pd.DataFrame({'Cat': categories}), df, how='outer')
Cat UR3 VR1 VR VR3
0 ATIDS 137.0 99.0 40.0 84.0
1 BasicCrane 2.0 8.0 3.0 1.0
2 LLP NaN NaN NaN NaN
3 Beam Sensor 27.0 12.0 13.0 14.0
4 CLPS 1.0 NaN NaN 1.0
5 SPR NaN NaN NaN NaN
One way you could easily do is to fill NaN value with 0 'before' doing a groupby function. All zero data (previously NaN value) will be totally be counted as zero.
df.fillna(0)

Convert two pandas rows into one

I want to convert below dataframe,
ID TYPE A B
0 1 MISSING 0.0 0.0
1 2 1T 1.0 2.0
2 2 2T 3.0 4.0
3 3 MISSING 0.0 0.0
4 4 2T 10.0 4.0
5 5 CBN 15.0 20.0
6 5 DSV 25.0 35.0
to:
ID MISSING_A MISSING_B 1T_A 1T_B 2T_A 2T_B CBN_A CBN_B DSV_A DSV_B
0 1 0.0 0.0 NaN NaN NaN NaN NaN NaN NaN NaN
1 2 NaN NaN 1.0 2.0 3.0 4.0 NaN NaN NaN NaN
3 3 0.0 0.0 NaN NaN NaN NaN NaN NaN NaN NaN
4 4 10.0 4.0 NaN NaN 10.0 4.0 NaN NaN NaN NaN
5 5 NaN NaN NaN NaN NaN NaN 15.0 20.0 25.0 35.0
For IDs with multiple types, multiple rows for A and B to merge into one row as shown above.
You are looking for a pivot, which will end up giving you a multi-index. You'll need to join those columns to get the suffix you are looking for.
df = df.pivot(index='ID',columns='TYPE', values=['A','B'])
df.columns = ['_'.join(reversed(col)).strip() for col in df.columns.values]
df.reset_index()

How to append to individual columns in a Pandas DataFrame

So I want to add/append data to a specific pandas dataFrame column but without it causing NaN values in the remaining columns
I.e.
DataFrame = pd.DataFrame(columns=["column1", "column2", "column3"])
for i in range():
DataFrame = DataFrame.append({"column1":int(i)}, ignore_index=True)
DataFrame = DataFrame.append({"column2":float(i*2)}, ignore_index=True)
DataFrame = DataFrame.append({"column3":int(i*5)}, ignore_index=True)
print(DataFrame)
This will return:
column1 column2 column3
0 0.0 NaN NaN
1 NaN 0.0 NaN
2 NaN NaN 0.0
3 1.0 NaN NaN
4 NaN 2.0 NaN
5 NaN NaN 5.0
6 2.0 NaN NaN
7 NaN 4.0 NaN
8 NaN NaN 10.0
What we want returned:
column1 column2 column3
0 0.0 0.0 0.0
1 1.0 2.0 5.0
2 2.0 4.0 10.0
I know I can in this case use one .append for all the different columns. But I have some cases where the data to be appended will vary based on multiple conditions. Hence I'd like to know if it's possible to append to single columns in a dataframe without producing NaN values in the remaining columns. So that I can avoid writing hundreds of if else statements.
Or if someone has any good idea regarding how to 'collapse' the NaN values (removing the NaN values without removing the entire row so that if there is a NaN value at index 0 in column 3 and there is a integer 5 at index 1 in the same column the integer 5 gets moved up to index 0)
Happy to hear any ideas.
IIUC for your current example you can try this:
DataFrame[['column2','column3']]=DataFrame[['column2','column3']].bfill()
Output:
column1 column2 column3
0 0.0 0.0 0.0
1 NaN 0.0 0.0
2 NaN 2.0 0.0
3 1.0 2.0 5.0
4 NaN 2.0 5.0
5 NaN 4.0 5.0
6 2.0 4.0 10.0
7 NaN 4.0 10.0
8 NaN 6.0 10.0
9 3.0 6.0 15.0
10 NaN 6.0 15.0
11 NaN 8.0 15.0
12 4.0 8.0 20.0
13 NaN 8.0 20.0
14 NaN NaN 20.0
then remove the NaN :
DataFrame.dropna(inplace=True)
Outpt:
column1 column2 column3
0 0.0 0.0 0.0
3 1.0 2.0 5.0
6 2.0 4.0 10.0
9 3.0 6.0 15.0
12 4.0 8.0 20.0

ReArrange Pandas DataFrame date columns in date order

I have a pandas dataframe that summarises sales by calendar month & outputs something like:
Month level_0 UNIQUE_ID 102018 112018 12018 122017 122018 22018 32018 42018 52018 62018 72018 82018 92018
0 SOLD_QUANTITY 01 3692.0 5182.0 3223.0 1292.0 2466.0 2396.0 2242.0 2217.0 3590.0 2593.0 1665.0 3371.0 3069.0
1 SOLD_QUANTITY 011 3.0 6.0 NaN NaN 7.0 5.0 2.0 1.0 5.0 NaN 1.0 1.0 3.0
2 SOLD_QUANTITY 02 370.0 130.0 NaN NaN 200.0 NaN NaN 269.0 202.0 NaN 201.0 125.0 360.0
3 SOLD_QUANTITY 03 2.0 6.0 NaN NaN 2.0 1.0 NaN 6.0 11.0 9.0 2.0 3.0 5.0
4 SOLD_QUANTITY 08 NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN 175.0 NaN NaN
I want to be able to programmatically re-arrange the column headers in ascending date order (eg starting 122017, 12018, 22018...). I need to do it in a way that is programmatic as every way the report runs, it will be a different list of months as it runs every month for last 365 days.
The index data type:
Index(['level_0', 'UNIQUE_ID', '102018', '112018', '12018', '122017', '122018',
'22018', '32018', '42018', '52018', '62018', '72018', '82018', '92018'],
dtype='object', name='Month')
Use set_index for only dates columns, convert them to datetimes and get order positions by argsort, then change ordering with iloc:
df = df.set_index(['level_0','UNIQUE_ID'])
df = df.iloc[:, pd.to_datetime(df.columns, format='%m%Y').argsort()].reset_index()
print (df)
level_0 UNIQUE_ID 122017 12018 22018 32018 42018 52018 \
0 SOLD_QUANTITY 1 1292.0 3223.0 2396.0 2242.0 2217.0 3590.0
1 SOLD_QUANTITY 11 NaN NaN 5.0 2.0 1.0 5.0
2 SOLD_QUANTITY 2 NaN NaN NaN NaN 269.0 202.0
3 SOLD_QUANTITY 3 NaN NaN 1.0 NaN 6.0 11.0
4 SOLD_QUANTITY 8 NaN NaN NaN NaN NaN NaN
62018 72018 82018 92018 102018 112018 122018
0 2593.0 1665.0 3371.0 3069.0 3692.0 5182.0 2466.0
1 NaN 1.0 1.0 3.0 3.0 6.0 7.0
2 NaN 201.0 125.0 360.0 370.0 130.0 200.0
3 9.0 2.0 3.0 5.0 2.0 6.0 2.0
4 NaN 175.0 NaN NaN NaN NaN NaN
Another idea is create month period index by DatetimeIndex.to_period, so is possible use sort_index:
df = df.set_index(['level_0','UNIQUE_ID'])
df.columns = pd.to_datetime(df.columns, format='%m%Y').to_period('m')
#alternative for convert to datetimes
#df.columns = pd.to_datetime(df.columns, format='%m%Y')
df = df.sort_index(axis=1).reset_index()
print (df)
level_0 UNIQUE_ID 2017-12 2018-01 2018-02 2018-03 2018-04 \
0 SOLD_QUANTITY 1 1292.0 3223.0 2396.0 2242.0 2217.0
1 SOLD_QUANTITY 11 NaN NaN 5.0 2.0 1.0
2 SOLD_QUANTITY 2 NaN NaN NaN NaN 269.0
3 SOLD_QUANTITY 3 NaN NaN 1.0 NaN 6.0
4 SOLD_QUANTITY 8 NaN NaN NaN NaN NaN
2018-05 2018-06 2018-07 2018-08 2018-09 2018-10 2018-11 2018-12
0 3590.0 2593.0 1665.0 3371.0 3069.0 3692.0 5182.0 2466.0
1 5.0 NaN 1.0 1.0 3.0 3.0 6.0 7.0
2 202.0 NaN 201.0 125.0 360.0 370.0 130.0 200.0
3 11.0 9.0 2.0 3.0 5.0 2.0 6.0 2.0
4 NaN NaN 175.0 NaN NaN NaN NaN NaN

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