NBA Python文件读取

Question

I have a homework assignment and we need to go through a file we created and take the players that have played more than 50 games and have an average shooting percentage of over 50 percent (which we have to calculate by dividing the two numbers).

I have formatted my code like this, because I am trying to index into the new lines I have created from the text. This is not working for me and I was wondering if anyone could point me in a new direction please. Thank you.

f = open("stats-clean.txt", "r")
lines = f.read()
for line in lines:
    new_lines = lines.split("\n")
report = []
new_lines.remove(new_lines[0])
for item in new_lines:
    if int(item[4])/int(item[5]) > .50 and int(item[3]) >= 50:
        report.append(item)
print(report)
f.close()

Answer 1

I'm not sure about the format of your input, but one problem is that you're trying to compare integers to floats. if you caste item[4] and item[5] as ints eg

int(item[4])/int(item[5]) > .50

then the resolution of the division above will always give you an int. So...

int(4)/int(5) = 0

But,

float(4)/float(5) = 0.8

So it is likely that you're not really making the comparison that you wanted, which could lead to that section of the if statement resolving to false.

Answer 2

Just to let you know, there is an easier way to do this, I just scripted this solution for fun.

import csv

with open('stats-clean.txt', 'rb') as f:
    reader = csv.reader(f)
    player_data = list(reader)

for i in player_data[1:]:
    name , pos, team, gp, fgm, fga = i
    if gp > 50:
        try:
            print 'Player: {0} Average Shooting per game {1}'.format(name, ( float(gp)/float(fga) ) )
        except ZeroDivisionError as e:
            print 'ZERO SHOTS : Player {} has {} shots'.format( name, fga )

Answer 3

A key problem here is that new_lines is a list of strings, for example

>>> new_lines[0]
'Julyan Stone,PG,DEN,4,0.5,0.5'

item[4] of this string is the character 'a' so when you go to cast with int you get ValueError: invalid literal for int() with base 10: 'a' .

You need to split each element of new_lines using split(',') . So for example

>>> new_lines[1].split(',')
['Chris Wilcox', 'PF', 'BOS', '61', '1.8', '2.5']

Now you can do your casting as item[4] is '1.8' and perform your conditional test but use floats instead of int to turn the strings into numbers as pointed out by @GC123UNC

Also notice that the loop

for line in lines:
    new_lines = lines.split("\n")

is superfluous: lines is a string: one split('\\n') gives you the list new_lines that you need. You need to loop through the elements of new_lines and split on , so that you can do your conditional test.

Instead of remove use slicing: newlines[1:] .

You might wish to consider using lines = f.readlines() rather than lines = f.read() . The latter returns a string that you need to split and then split again. The former gives you a list which you can strip() and split on , (something like line.strip().split(',') )