Question

例如，我想使用python从文本文件中取出前30％的数据。

以下是我尝试生成两个新文件的一些代码，但我不知道如何获取一定比例的数据并将其写入。

就是这样：

import sys

def NewFile(FileName):
        open(FileName,'r')
        print('Creating new text file')
        #A for 70% training data
        AFileName = 'A'+FileName
        #B for 30% testing data
        BFileName = 'B'+FileName

        try:
                afile = open(AFileName,'a')
                bfile = open(BFileName,'a')
                afile.close()
                bfile.close()
        except:
                print('~~~~~~')
                sys.exist(0)

Answer 1

这将有效

import sys

def NewFile(FileName):
    lines = open(FileName, 'r').readlines()
    print('Creating new text file')
    num_lines = len(lines)
    num_lines_a = 0.7 * num_lines
    #A for 70% training data
    AFileName = 'A'+FileName
    #B for 30% testing data
    BFileName = 'B'+FileName

    try:
        afile = open(AFileName,'a')
        bfile = open(BFileName,'a')
        a = 1
        for line in lines:
            if a <= num_lines_a:
                afile.write(line)
                a +=1 
            else:
                bfile.write(line)
        afile.close()
        bfile.close()
    except:
            print('~~~~~~')
            sys.exist(0)

Answer 2

听起来你想要这些内容，filename是您正在阅读的文件，proportion是您想要的第一个文件中的百分比：

def split_file(filename, tofile, othertofile, proportion):
    content = open(filename).readlines()
    number_of_lines = len(content)

    # Split content.
    first_portion = "\n".join(content[:number_of_lines * proportion])
    second_portion = "\n".join(content[number_of_lines * proportion:])

    # Write to files.
    open(tofile, "w").write(first_portion)
    open(othertofile, "w").write(second_portion)

Answer 3

另一种方法：

from itertools import islice


def new_file(old_filename):
    with open(old_filename, 'r') as old_file:
        lines = list(old_file)
    training_file_line_count = int(len(lines) * 0.7)
    lines_iter = iter(lines)
    with open('A' + old_filename, 'w') as training_file:
        training_file.writelines(islice(lines_iter, training_file_line_count))
    with open('B' + old_filename, 'w') as testing_data_file:
        testing_data_file.writelines(lines_iter)

从txt文件中获取一定数量的数据

3 个答案: