python 删除文件某一行

python 删除文件某一行

#!/usr/bin/python
# -*- coding: utf-8 -*-
# @Time    : 2020/6/29 15:06
# @Author  : hyang
# @File    : delLine.py
# @Software: PyCharm

import sys
import os
import random
import shutil
import string


def getLine_num(filename):
    count = 0
    for index, line in enumerate(open(filename, 'rb')):
        count += 1
    return count


def remove_Line(filename, del_line):
    """
    删除文件某一行
    :param filename:
    :param del_line:
    :return:
    """
    # 打开旧文件
    old_file = open(filename, "rb")
    # 打开新文件
    new_file = open("%s.new" % filename, "wb")

    current_line = 0
    # 定位到需要删除的行
    while current_line < (del_line - 1):
        current_line_cont = old_file.readline()
        # 把每一行写入新文件
        new_file.write(current_line_cont)
        current_line += 1

    # 当前光标在被删除行的行首，记录该位置
    seek_point = old_file.tell()

    # 设置光标位置
    new_file.seek(seek_point, 0)

    # 读需要删除的行，光标移到下一行行首
    line_con = old_file.readline()
    print("需要删除行: {}".format(line_con))

    # 被删除行的下一行读给 next_line
    next_line = old_file.readline()

    # 连续覆盖剩余行，后面所有行上移一行
    while next_line:
        new_file.write(next_line)
        next_line = old_file.readline()

    # 文件关闭
    old_file.close()
    new_file.close()

    # 文件备份与替换
    bak_f = filename + ''.join(random.sample(string.digits, 6))
    os.rename(filename, bak_f)  # 备份旧文件
    print("源文件备份为%s" % bak_f)
    os.rename("%s.new" % filename, filename)  # 把新文件名字改成原文件的名字，就把之前的覆盖掉了


# def main_arg():
#     if len(v_arg) != 2:
#         # print(platform.system())
#         print_arg(v_arg)
#         print_warn("---参数输入错误--")
#         print_warn("delLine 文件名 删除行")
#     else:
#         f_name = v_arg[1].strip()
#         line_no = v_arg[2].strip()  # 删除行
#     if not line_no.isdigit():
#         print_error("行数必须为数字" )
#     else:
#         if not os.path.exists(f_name):
#             print("%s文件不存在" % f_name)
#     else:
#         pass


def main():
    f_name = 'F:a/logs'
    bak_f = f_name + ''.join(random.sample(string.digits, 6))
    line_no = '2'
    line_no = int(line_no)

    line_num = getLine_num(f_name)  # 获得文件总行数
    if line_no > line_num:
        print("行数大于文件行数 " + line_num)
    else:
        print("文件总行数={},删除第{}行" .format(line_num, line_no))
        remove_Line(f_name, line_no)


if __name__ == '__main__':
    # 获得系统参数
    # v_arg = sys.argv
    # main_arg()
    # init(autoreset=True)  # 初始化，并且设置颜色设置自动恢复
    main()
    # print_color(Style.RESET_ALL)  # 还原默认颜色