Question

我得到了这个，但我该怎么做呢：

['99', '88', '77', '66\n', '11', '22', '33', '44\n', '78', '58', '68', '88\n']

为：

[[99, 88, 77, 66], [11, 22, 33, 44], [78, 58, 68, 88]]

这是我用来获得第一个输出的函数：

def class_avg(open_file):
    new = []
    number = []

    for i in open_file:
        student = i.split(',')
        for grade in student[4:]:
            new.append(grade)
    return new

这是文件格式：

Smith, Joe,9911991199,smithjoe9,99,88,77,66
Ash, Wood,9912334456,ashwood,11,22,33,44
Full, Kare,9913243567,fullkare,78,58,68,88

Answer 1

以下是您应该如何阅读处理文件以避免问题：

def class_avg(open_file):
    new = []    
    for line in open_file:
        student = line.strip().split(',')
        new.append(list(map(int, student[4:])))
    return new

正如@ Jean-FrançoisFabre指出，如果你要转换为.strip，因为它处理空格，int并不是必需的。你真的可以这样做：

return [[int(s) for s in line.split()[4:]] for line in open_file]

或者更好的是，使用csv模块：

import csv
with open('path_to_my_file.txt') as f:
    reader = csv.reader(f)
    data = [[int(x) for x in row[4:]] for row in reader]

Answer 2

尝试这样的事情

output = []
sub_l = []
for i in your_input:
    if "\n" in i:
        sub_l.append(int(i.replace("\n","")))
        output.append(sub_l)
        sub_l=[]
    else:
        sub_l.append(int(i))

print(output)

Answer 3

如果你喜欢迭代技巧......

enctype

Answer 4

l=['99', '88', '77', '66\n', '11', '22', '33', '44\n', '78', '58', '68', '88\n']

y=[]
z=[]

for x in l:
    y.append(int(x))
    if '\n' in x:
        z.append(y)
        y=[]

print (z)

输出

[[99, 88, 77, 66], [11, 22, 33, 44], [78, 58, 68, 88]]

Answer 5

尝试此功能：如果要更改子列表的长度，可以更改步进器。

def list_divider(ls,stepper=4):
    #Get rid of the \n.
    ls=list(map(str.strip,ls))
    result=[]
    pos = 0
    #Slice the list  by moving pos 4 steps each time
    while pos<=len(ls)-1:
        result.append(ls[pos:pos+stepper])
        pos+=stepper
    return result

我希望这很有帮助

Answer 6

这是一个相当简洁的方法，使用csv模块读取文件，itertools模块重新格式化数据以进行计算。

import csv
import itertools

def class_avg(open_file):
    grades = tuple(itertools.chain.from_iterable(  # Put all grades into single sequence.
                    itertools.chain(map(int, row[4:])  # Convert grades in row to integers.
                        for row in csv.reader(open_file))))
    total = sum(grades)
    return total / len(grades)

with open('class_grades.txt', newline='') as file:
    print(class_avg(file))  # -> 61.0

打印的值适用于您问题中示例文件中的值。

字符串列表到字符串子列表

6 个答案: