python - 从文本文件中过滤行

Question

我必须清除一个txt文件（test.txt），删除以'（'或空行开头的行，然后重命名它（test_ok.txt）

我使用这个功能：

def clearfile(filename):
    for row in (open (filename, 'r')).readlines():
        if row[0][0]<>'\n' and riga[0][0]<>'(' :
            out_file = open('%s_%s%s' %(os.path.splitext(filename)[0],'ok',os.path.splitext(os.path.basename(filename))[1]) , 'a')
            out_file.write(riga) 
            out_file.close()
    return out_file

它可以工作，但速度很慢。有什么优化技巧吗？

这是我的新功能：

def clearfile(filename):
    with open (filename, 'r') as a, open('%s_%s%s' %(os.path.splitext(filename)[0],'ok',os.path.splitext(os.path.basename(filename))[1]) , 'a') as b:
        for row in (a).readlines():
            if row[0][0]!='\n' and row[0][0]!= '(' :
                b.write(row) 
        b.close

Answer 1

为什么要多次打开/关闭文件？

def clearfile(filename):
    out_file = open('%s_%s%s' %(os.path.splitext(filename)[0], 'ok', os.path.splitext(os.path.basename(filename))[1]) , 'a')
    for row in (open (filename, 'r')).readlines():
        if row[0][0]!= '\n' and riga[0][0]!='(' :
            out_file.write(riga) 
    out_file.close()
    return out_file

Answer 2

尝试这样的事情：

import os
def clear_and_move(infname, outfname):
    with open(infname, 'r') as inf, open(outfname, 'w+') as outf:
        # write new file as a copy of the first
        # skip lines that contain only whitespace or start with '('
        outf.writelines(line for line in inf 
                        if line.strip() and not line.startswith('('))
    # delete the original file
    os.remove(infname)