Pandas filter maximum groupby - pandas

I have Pandas df:
family age fruits
------------------
Brown 12 7
Brown 33 5
Yellow 28 3
Yellow 11 9
I want to get ages with next conditions:
Group by family;
Having maximum of fruits
So result df will be:
family age
-----------
Brown 12
Yellow 11

We can do:
(df.sort_values(['family','fruits'], ascending=[True,False])
.drop_duplicates('family')
)
Output:
family age fruits
0 Brown 12 7
3 Yellow 11 9
Or with groupby().idxmax()
df.loc[df.groupby('family').fruits.idxmax(), ['family','age'] ]
Output:
family age
0 Brown 12
3 Yellow 11

Use head after sort_values
df.sort_values(
['family','fruits'], ascending=[True,False])
.groupby('family').head(1)

Related

compare value in two rows in a column pandas

I have a pandas df something like this:
color pct days text
1 red 5 7 good
2 red 10 30 good
3 red 11 60 bad
4 blue 6 7 bad
5 blue 15 30 good
6 blue 21 60 bad
7 yellow 2 7 good
8 yellow 5 30 bad
9 yellow 7 60 bad
So basically, for each color, I have percentage values for 7 days, 30 days and 60 days. Please note that these are not always in correct order as I gave in example above. My task now is to look at the change in percentage for each color between the consecutive days values and if the change is greater or equal to 5%, then write in column "text" as "NA". Text in days 7 category is default and cannot be overwritten.
Desired result:
color pct days text
1 red 5 7 good
2 red 10 30 NA
3 red 11 60 bad
4 blue 6 7 bad
5 blue 15 30 NA
6 blue 21 60 NA
7 yellow 2 7 good
8 yellow 5 30 bad
9 yellow 7 60 bad
I am able to achieve this by a very very long process that I am very sure is not efficient. I am sure there is a much better way of doing this, but I am new to python, so struggling. Can someone please help me with this? Many thanks in advance
A variation on a (now-deleted) suggested answer as comment:
# ensure numeric data
df['pct'] = pd.to_numeric(df['pct'], errors='coerce')
df['days'] = pd.to_numeric(df['days'], errors='coerce')
# update in place
df.loc[df.sort_values(['color','days'])
.groupby('color')['pct']
.diff().ge(5), 'text'] = 'NA'
Output:
color pct days text
1 red 5 7 good
2 red 10 30 NA
3 red 11 60 bad
4 blue 6 7 bad
5 blue 15 30 NA
6 blue 21 60 NA
7 yellow 2 7 good
8 yellow 5 30 bad
9 yellow 7 60 bad
In the code below I'm reading your example table into a pandas dataframe using io, you don't need to do this, you already have your pandas table.
import pandas as pd
import io
df = pd.read_csv(io.StringIO(
""" color pct days text
1 red 5 7 good
2 red 10 30 good
3 red 11 60 bad
4 blue 6 7 bad
5 blue 15 30 good
6 blue 21 60 bad
7 yellow 2 7 good
8 yellow 5 30 bad
9 yellow 7 60 bad"""
),delim_whitespace=True)
not_seven_rows = df['days'].ne(7)
good_rows = df['pct'].lt(5)
#Set the rows which are < 5 and not 7 days to be 'good'
df.loc[good_rows & not_seven_rows, 'text'] = 'good'
#Set the rows which are >= 5 and not 7 days to be 'NA'
df.loc[(~good_rows) & not_seven_rows, 'text'] = 'NA'
df
Output
def function1(dd:pd.DataFrame):
dd1=dd.sort_values("days")
return dd1.assign(text=np.where(dd1.pct.diff()>=5,"NA",dd1.text))
df1.groupby('color',sort=False).apply(function1).reset_index(drop=True)
out
color pct days text
0 red 5 7 good
1 red 10 30 NA
2 red 11 60 bad
3 blue 6 7 bad
4 blue 15 30 NA
5 blue 21 60 NA
6 yellow 2 7 good
7 yellow 5 30 bad
8 yellow 7 60 bad

How do you groupby and aggregate using conditional statements in Pandas?

Expanding on the question here, I'm wondering how to add aggregation to the following based on conditions:
Index Name Item Quantity
0 John Apple Red 10
1 John Apple Green 5
2 John Orange Cali 12
3 Jane Apple Red 10
4 Jane Apple Green 5
5 Jane Orange Cali 18
6 Jane Orange Spain 2
7 John Banana 3
8 Jane Coconut 5
9 John Lime 10
... And so forth
What I need to do is getting this data converted into a dataframe like the following. Note: I am only interested in getting the total quantity of the apples and oranges both of them in separate columns, i.e. whatever other items appear in a certain group are not to be included in the aggregation done on column "Quantity" (but they are still to appear in the column "All items" as strings):
Index Name All Items Apples Total Oranges Total
0 John Apple Red, Apple Green, Orange Cali, Banana, Lime 15 12
1 Jane Apple Red, Apple Green, Orange Cali, Coconut 15 20
How would do I achieve that? Many thanks in advance!
You can use groupby and pivot_table after extracting Apple and Orange sub strings as below:
import re
s = df['Item'].str.extract("(Apple|Orange)",expand=False,flags=re.I)
# re.I used above is optional and is used for case insensitive matching
a = df.assign(Item_1=s).dropna(subset=['Item_1'])
out = (a.groupby("Name")['Item'].agg(",".join).to_frame().join(
a.pivot_table("Quantity","Name","Item_1",aggfunc=sum).add_suffix("_Total"))
.reset_index())
print(out)
Name Item Apple_Total \
0 Jane Apple Red,Apple Green,Orange Cali,Orange Spain 15
1 John Apple Red,Apple Green,Orange Cali 15
Orange_Total
0 20
1 12
EDIT:
For edited question, you can use the same code only except groupby on the original dataframe df instead of the subset a and then join:
out = (df.groupby("Name")['Item'].agg(",".join).to_frame().join(
a.pivot_table("Quantity","Name","Item_1",aggfunc=sum).add_suffix("_Total"))
.reset_index())
print(out)
Name Item Apple_Total \
0 Jane Apple Red,Apple Green,Orange Cali,Orange Spain... 15
1 John Apple Red,Apple Green,Orange Cali,Banana,Lime 15
Orange_Total
0 20
1 12
First Filter only the required rows using str.contains on the column Item
from io import StringIO
import pandas as pd
s = StringIO("""Name;Item;Quantity
John;Apple Red;10
John;Apple Green;5
John;Orange Cali;12
Jane;Apple Red;10
Jane;Apple Green;5
Jane;Orange Cali;18
Jane;Orange Spain;2
John;Banana;3
Jane;Coconut;5
John;Lime;10
""")
df = pd.read_csv(s,sep=';')
req_items_idx = df[df.Item.str.contains('Apple|Orange')].index
df_filtered = df.loc[req_items_idx,:]
Once you have them you can further pivot the data to get the required values based on Name
pivot_df = pd.pivot_table(df_filtered,index=['Name'],columns=['Item'],aggfunc='sum')
pivot_df.columns = pivot_df.columns.droplevel()
pivot_df.columns.name = None
pivot_df = pivot_df.reset_index()
Generate the Totals for Apples and Oranges
orange_columns = pivot_df.columns[pivot_df.columns.str.contains('Orange')].tolist()
apple_columns = pivot_df.columns[pivot_df.columns.str.contains('Apple')].tolist()
pivot_df['Apples Total'] = pivot_df.loc[:,apple_columns].sum(axis=1)
pivot_df['Orange Total'] = pivot_df.loc[:,orange_columns].sum(axis=1)
A wrapper function to combine the Items together
def combine_items(inp,columns):
res = []
for val,col in zip(inp.values,columns):
if not pd.isnull(val):
res += [col]
return ','.join(res)
req_columns = apple_columns+orange_columns
pivot_df['Items'] = pivot_df[apple_columns+orange_columns].apply(combine_items,args=([req_columns]),axis=1)
Finally you can get the required columns in a single place and print the values
total_columns = pivot_df.columns[pivot_df.columns.str.contains('Total')].tolist()
name_item_columns = pivot_df.columns[pivot_df.columns.str.contains('Name|Items')].tolist()
>>> pivot_df[name_item_columns+total_columns]
Name Items Apples Total Orange Total
0 Jane Apple Green,Apple Red,Orange Cali,Orange Spain 15.0 20.0
1 John Apple Green,Apple Red,Orange Cali 15.0 12.0
The answer is intended to outline the individual steps and approach one can take to solve something similar to this
Edits: fixed a bug.
To do this, before doing your groupby you can create your Total columns. These will contain a the number of apples and oranges in that row, depending whether that row's Item is apple or orange.
df['Apples Total'] = df.apply(lambda x: x.Quantity if ('Apple' in x.Item) else 0, axis=1)
df['Oranges Total'] = df.apply(lambda x: x.Quantity if ('Orange' in x.Item) else 0, axis=1)
When this is in place, groupby name and aggregate on each column. Sum on the total columns, and aggregate to list on the item column.
df.groupby('Name').agg({'Apples Total': 'sum',
'Oranges Total': 'sum',
'Item': lambda x: list(x)
})
df = pd.read_csv(StringIO("""
Index,Name,Item,Quantity
0,John,Apple Red,10
1,John,Apple Green,5
2,John,Orange Cali,12
3,Jane,Apple Red,10
4,Jane,Apple Green,5
5,Jane,Orange Cali,18
6,Jane,Orange Spain,2
7,John,Banana,3
8,Jane,Coconut,5
9,John,Lime,10
"""))
Getting list of items
grouping by name to get the list of items
items_list = pd.DataFrame(df.groupby(["Name"])["Item"].apply(list)).rename(columns={"Item": "All Items"})
items_list
All Items
Name
Jane [Apple Red, Apple Green, Orange Cali, Orange Spain, Coconut]
John [Apple Red, Apple Green, Orange Cali, Banana, Lime]
getting count of name item groups
renaming the temp df items column such that all the apples/oranges are treated similarly
temp2 = df.groupby(["Name", "Item"])['Quantity'].apply(sum)
temp2 = pd.DataFrame(temp2).reset_index().set_index("Name")
temp2['Item'] = temp2['Item'].str.replace(r'(?:.*)(apple|orange)(?:.*)', r'\1', case=False,regex=True)
temp2
Item Quantity
Name
Jane Apple 5
Jane Apple 10
Jane Coconut 5
Jane Orange 18
Jane Orange 2
John Apple 5
John Apple 10
John Banana 3
John Lime 10
John Orange 12
getting the required pivot table
pivot table for getting items count as separate column and retaining just apple orange count
pivot_df = pd.pivot_table(temp2, values='Quantity', columns='Item', index=["Name"], aggfunc=np.sum)
pivot_df = pivot_df[['Apple', 'Orange']]
pivot_df
Item Apple Orange
Name
Jane 15.0 20.0
John 15.0 12.0
merging the items list df and the pivot_df
output = items_list.merge(pivot_df, on="Name").rename(columns = {'Apple': 'Apples
Total', 'Orange': 'Oranges Total'})
output
All Items Apples Total Oranges Total
Name
Jane [Apple Red, Apple Green, Orange Cali, Orange Spain, Coconut] 15.0 20.0
John [Apple Red, Apple Green, Orange Cali, Banana, Lime] 15.0 12.0

How do you “pivot” using conditions, aggregation, and concatenation in Pandas?

I have a dataframe in a format such as the following:
Index Name Fruit Quantity
0 John Apple Red 10
1 John Apple Green 5
2 John Orange Cali 12
3 Jane Apple Red 10
4 Jane Apple Green 5
5 Jane Orange Cali 18
6 Jane Orange Spain 2
I need to turn it into a dataframe such as this:
Index Name All Fruits Apples Total Oranges Total
0 John Apple Red, Apple Green, Orange Cali 15 12
1 Jane Apple Red, Apple Green, Orange Cali, Orange Spain 15 20
Question is how do I do this? I have looked at the groupby docs as well as a number of posts on pivot and aggregation but translating that into this use case somehow escapes me. Any help or pointers much appreciated.
Cheers!
Use GroupBy.agg with join, create column F by split and pass to DataFrame.pivot_table, last join together by DataFrame.join:
df1 = df.groupby('Name', sort=False)['Fruit'].agg(', '.join)
df2 = (df.assign(F = df['Fruit'].str.split().str[0])
.pivot_table(index='Name',
columns='F',
values='Quantity',
aggfunc='sum')
.add_suffix(' Total'))
df3 = df1.to_frame('All Fruits').join(df2).reset_index()
print (df3)
Name All Fruits Apple Total \
0 John Apple Red, Apple Green, Orange Cali 15
1 Jane Apple Red, Apple Green, Orange Cali, Orange Spain 15
Orange Total
0 12
1 20

Groupby sum of two column and create new dataframe in pandas

I have a dataframe as shown below
Player Goal Freekick
Messi 2 5
Ronaldo 1 4
Messi 1 4
Messi 0 5
Ronaldo 0 9
Ronaldo 1 8
Xavi 1 1
Xavi 0 7
From the above I would like do groupby sum of Goal and Freekick as shown below.
Expected Output:
Player toatal_goals total_freekicks
Messi 3 14
Ronaldo 2 21
Xavi 1 8
I tried below code:
df1 = df.groupby(['Player'])['Goal'].sum().reset_index().rename({'Goal':'toatal_goals'})
df1['total_freekicks'] = df.groupby(['Player'])['Freekick'].sum()
But above one does not work, please help me..
First aggregate sum by Player, then DataFrame.add_prefix and convert columns names to lowercase:
df = df.groupby('Player').sum().add_prefix('total_').rename(columns=str.lower)
print (df)
total_goal total_freekick
Player
Messi 3 14
Ronaldo 2 21
Xavi 1 8
You can use namedagg to create the aggregations with customized column names.
(
df.groupby(by='Player')
.agg(toatal_goals=('Goal', 'sum'),
total_freekicks=('Freekick', 'sum'))
.reset_index()
)
Player toatal_goals total_freekicks
Messi 3 14
Ronaldo 2 21
Xavi 1 8

Pandas - use pivot_table to convert each unique element in 1 column into a unique column

I am trying to expand a dataframe such that for all the unique elements in the rows of one column, each value becomes a column in its own right.
I start with a dataframe that looks like this.
Colour Age Type Count
0 Black 11yrs Cats 22
1 Black 12yrs Cats 2
2 White 8yrs Dogs 10
3 Brown 11yrs Dogs 2
4 White 12yrs Cats 14
I would like to change the dataframe, such that the columns are the unique elements of Colour column, Black, White, Brown - so that it looks like this:
Age Type Black White Brown
0 11yrs Cats 22 0 0
1 12yrs Cats 2 14 0
2 8yrs Dogs 0 10 0
3 11yrs Dogs 0 0 2
I've tried a few approaches but clearly I am missing something.
Any help appreciated.
You may use pivot_table as follows:
(df.pivot_table(index=['Age', 'Type'],
columns='Colour',
values='Count',
fill_value=0).reset_index())
Out[22]:
Colour Age Type Black Brown White
0 11yrs Cats 22 0 0
1 11yrs Dogs 0 2 0
2 12yrs Cats 2 0 14
3 8yrs Dogs 0 0 10
Or set_index and unstack
(df.set_index(['Age', 'Type', 'Colour']).Count.unstack(fill_value=0)
.reset_index())
Out[23]:
Colour Age Type Black Brown White
0 11yrs Cats 22 0 0
1 11yrs Dogs 0 2 0
2 12yrs Cats 2 0 14
3 8yrs Dogs 0 0 10