python当目录不存在时创建create_dir_if_not

方法1：参照argparse模块，实现当目录不存在时创建

#-*- coding: utf-8 -*-
import os
import argparse

def create_dir_if_not_there(path, dir_name):
    """ Checks to see if a directory exists in the users home directory, if not then create it. """
    if not os.path.exists(dir_name):
        os.mkdir(os.path.join(path, dir_name))

def get_parser():
    """" get parser """
    current_path = os.getcwd()
    parser = argparse.ArgumentParser(description='create dir if not there')
    parser.add_argument('-path', '--p', default=current_path) # default 默认为当前路径
    parser.add_argument('-dirname', '--d', default='test')
    args = parser.parse_args()
    path = args.p
    dir_name = args.d
    return path, dir_name


def main():
    """ main func """
    path, dir_name = get_parser()
    create_dir_if_not_there(path, dir_name)


if __name__ == '__main__':
    main()

测试结果
测试case1：

test1.png

测试case2：

test2.png
测试case3：采用argparse默认path，默认目录名，同样可以创建目录
test3.png
注：方法1中的os.mkdir只能创建最后一级目录，。os.makedirs可以递归创建目录。具体参照github，如下：

https://github.com/geekcomputers/Python/blob/master/create_dir_if_not_there.py

os.path.expanduser('~')表示用户主目录。参见：https://docs.python.org/2.7/library/os.path.html?highlight=expanduser#os.path.expanduser

#-*- coding: utf-8 -*-
import os

def create_dir_if_not_there(dir):
    """ Checks to see if a directory exists in the users home directory, if not then create it. """
    try:
        rootpath = os.path.expanduser('~')
        if not os.path.exists(os.path.join(rootpath, dir)):
            os.makedirs(os.path.join(rootpath, dir))
    except Exception as e:
        print e

def main():
    """ main func """
    create_dir_if_not_there('hello/world/test.py')


if __name__ == '__main__':
    main()

测试结果：

test4.png