python 3.x - How to sum up combined string has serval numbers in a pandas DataFrame column -


i have string contains comma delimited int values, such x = "1,2,3,4,5,6" , how calculate sum of x contained values?

i tried:

values = x.split(",").map(lambda a:int(a)) sum(values)

attributeerror: 'list' object has no attribute 'map'

actually, have pandas dataframe have such data format:

import numpy np import pandas pd df = pd.dataframe({'id':[100,101,201],                    'prices_a':['1,2,3','4,5,6','7,8,9'],                    'prices_b':['1,2,3','2,6,6','3,5,8']})

so be:

   id     prices_a prices_b 0  100    1,2,3    1,2,3 1  101    4,5,6    2,6,6 2  201    7,8,9    3,5,8

i add new column diff compare prices_a & prices_b, if same, df['diff'] = 'match', otherwise, df['diff'] = sum(prices_a values) - sum(prices_b b values)

you can use numpy.where, sums columns use str.split, astype sum per rows (axis=1):

a = df['prices_a'].str.split(',', expand=true).astype(float).sum(axis=1) b = df['prices_b'].str.split(',', expand=true).astype(float).sum(axis=1)  print (a) 0     6.0 1    15.0 2    24.0 dtype: float64  print (b) 0     6.0 1    14.0 2    16.0 dtype: float64  df['df'] =  np.where(df['prices_a'] == df['prices_b'], 'match', - b) print (df)     id prices_a prices_b     df 0  100    1,2,3    1,2,3  match 1  101    4,5,6    2,6,6    1.0 2  201    7,8,9    3,5,8    8.0

but better not mixed strings numeric.

so possible use e.g nans instead match:

df['diff'] =  np.where(df['prices_a'] == df['prices_b'], np.nan, - b) print (df)     id prices_a prices_b  diff 0  100    1,2,3    1,2,3   nan 1  101    4,5,6    2,6,6   1.0 2  201    7,8,9    3,5,8   8.0

Comments

Post a Comment

Popular posts from this blog

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

i'm implementing inapp billing in android app. works well, however, i'm trying decouple broadcast receiver activity manifest. suggestion in android's trivialdrive sample: // important: dynamically register broadcast messages updated purchases. // register receiver here instead of <receiver> in manifest // because call getpurchases() @ startup, therefore can ignore // broadcasts sent while app isn't running. // note: registering listener in activity bad idea, done here // because sample. regardless, receiver must registered after // iabhelper setup, before first call getpurchases(). currently there's class extends broadcastreceiver : public class iabbroadcastreceiver extends broadcastreceiver { /** * intent action receiver should filter for. */ public static final string action = "com.android.vending.billing.purchases_updated"; private final iabbroadcastlistener mlistener; public iabbroadcastreceiver(iabbroadcastlistener listener) { m...
Read more

python Tkinter Capturing keyboard events save as one single string -

is possible store keyboard events 1 string? code below stores 1 char , prints it. card reader or bar code reader, contains collection of character/ string not 1 character @ time. goal save char pressed text variable. from tkinter import * root = tk() def key(event): text= event.char text+= event.char print ("pressed", text) def callback(event): frame.focus_set() print ("clicked at", event.x, event.y) frame = frame(root, width=100, height=100) frame.bind("<key>", key) frame.bind("<button-1>", callback) frame.pack() root.mainloop() currently, creating text variable , everytime key() function gets called, , text stores last character typed. you can define text module level variable , , use module level text inside key function - text = '' def key(event): global text text+= event.char print("pressed", text)
Read more

sql server - Why does Linq-to-SQL add unnecessary COUNT()? -

here tables: create table customer ( cid int primary key, name varchar(32) ) create table ord ( oid int primary key, cid int foreign key references customer, address varchar(20) ) here's linq-to-sql statement: var aaa = c in db.customer select new { c, o = c.ord.tolist() }; and here's inexplicable query generated linq-to-sql: select [t0].[cid] [cid], [t0].[name] [name], [t1].[oid] [oid], [t1].[cid] [cid2], [t1].[address] [address], (select count(*) [dbo].[ord] [t2] [t2].[cid] = [t0].[cid]) [value] [dbo].[customer] [t0] left outer join [dbo].[ord] [t1] on [t1].[cid] = [t0].[cid] order [t0].[cid], [t1].[oid] i want understand how rid of count(*) part. it's entirely uncalled for! linq needs count(*) in order determine number of entries returned o = c.ord.tolist() .
Read more