Агрегирование CSV записей Использование Python

Question

Мой файл CSV выглядит следующим образом:

Mike,6 
Mike,5 
Bill,3 
Bill,1 
Sally,4 
Sally,2 

Я хотел бы изменить это так отсчеты суммируются по имени и выглядит следующим образом:

Mike,11 
Bill,4 
Sally,6 

Answer 1

Посмотрите на библиотека панд.

df = pd.read_csv('data.csv') 
df_grouped = df.groupby('name').sum() 

Более подробно здесь

http://pandas.pydata.org/pandas-docs/stable/groupby.html

Answer 2

def records_from_file(fname, column_names): 
    with open(fname,'r') as input_handler: 
    for line in input_handler: 
     line = line.strip('\n') #strip out newline 
     x={} #this creates x as an empty dictionary 
     for i in range(len(column_names)): 
      x[column_names[i]] = line.split(",")[i] #append each key and value to the dictionary 
     yield x 

record_stream = records_from_file('names.csv',['name', 'count']) 

class Object:     #Object to store unique data 
    def __init__(self, name, count): 
     self.name = name 
     self.count = count 

rownum = 0 #Row Number currently iterating over 
list = [] #List to store objects 

def checkList(name, count): 
    for object in list: #Iterate through list   
     count=int(count) 
     if object.name == name: #Check if name and produce combination exists 
      object.count += int(count) #If it does add to amount variable and break out 
      return 
    newObject = Object(name, count) #Create a new object with new name, produce, and amount 
    list.append(newObject) #Add to list and break out 

for record in record_stream: #Iterate through all the rows 
    name = record['name'] #Store name 
    count = int(record['count']) #Store count 
    checkList(name, count) 

rownum += 1 

for each in list: #Print out result 
    print each.name,each.count 

Answer 3

import pandas as pd 

df = pd.read_csv('names.csv') 
df.columns = ['name','count'] 
df_grouped = df.groupby('name').sum() 
print df_grouped