返回.txt文件内容

Question

I have a file, Testing.txt :

type,stan,820000000,92

paul,tanner,820000095,54

remmy,gono,820000046,68

bono,Jose,820000023,73

simple,rem,820000037,71

I'm trying to create a function that takes this file and returns:

• The average of all the grades (last numbers in the file of each line),
• and the ID (long numbers within file) of the highest and lowest grades.

I know how to get the average but am stuck trying to get the IDs.

So far my code looks like this:

#Function:

def avg_file(filename):

    with open(filename, 'r') as f:
        data = [int(line.split()[2]) for line in f]
        return sum(data)/len(data)


    avg =  avg_file(filename)

    return avg


#main program:

import q3_function

filename = "testing.txt"

average = q3_function.avg_file(filename)

print (average)

Answer 1

You can use a list comprehension to get the desire pairs of ID and score :

>>>l= [i.split(',')[-2:] for i in open(filename, 'r') if not i=='\n']
[['820000000', '92'], ['820000095', '54'], ['820000046', '68'], ['820000023', '73'], ['820000037', '71']]

Then for calculation the average you can use zip within map and sum functions:

>>> avg=sum(map(int,zip(*l)[1]))/len(l)
>>> avg
71

And for min and max use built-in functions min and max with a proper key :

max_id=max(l,key=itemgetter(1))[0]
min_id=min(l,key=itemgetter(1))[0]

Demo :

>>> from operator import itemgetter
>>> max(l,key=itemgetter(1))
['820000000', '92']
>>> max(l,key=itemgetter(1))[0]
'820000000'
>>> min(l,key=itemgetter(1))[0]
'820000095'
>>> min(l,key=itemgetter(1))
['820000095', '54']
>>> min(l,key=itemgetter(1))[0]
'820000095'

Answer 2

I think using the python csv module would help. Here is several examples : http://nbviewer.ipython.org/github/rasbt/python_reference/blob/master/tutorials/sorting_csvs.ipynb