Python 如何使用argparse打开文件？
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How to open file using argparse?
提问by nuT707
I want to open file for reading using argparse. In cmd it must look like: my_program.py /filepath
我想使用 argparse 打开文件进行读取。在 cmd 中它必须看起来像：my_program.py /filepath
That's my try:
这是我的尝试：
parser = argparse.ArgumentParser()
parser.add_argument('file', type = file)
args = parser.parse_args()
采纳答案by wim
The type of the argument should be string (which is default anyway). So make it like this:
参数的类型应该是字符串（无论如何都是默认的）。所以让它像这样：
parser = argparse.ArgumentParser()
parser.add_argument('filename')
args = parser.parse_args()
with open(args.filename) as file:
# do stuff here
回答by ilent2
Take a look at the documentation: http://docs.python.org/2/library/argparse.html#type
看一下文档：http: //docs.python.org/2/library/argparse.html#type
import argparse
parser = argparse.ArgumentParser()
parser.add_argument('file', type=argparse.FileType('r'))
args = parser.parse_args()
print args.file.readlines()
回答by yPhil
This implementation allows the "file name" parameter to be optional, as well as giving a short description if and when the user enters the -hor --helpargument.
此实现允许“文件名”参数是可选的，并在用户输入-hor--help参数时提供简短描述。
parser = argparse.ArgumentParser(description='Foo is a program that does things')
parser.add_argument('filename', nargs='?')
args = parser.parse_args()
if args.filename is not None:
print('The file name is {}'.format(args.filename))
else:
print('Oh well ; No args, no problems')
回答by Ming
In order to have the file closed gracefully, you can combine argparse.FileType with the "with" statement
为了优雅地关闭文件，您可以将 argparse.FileType 与“with”语句结合使用
# ....
parser.add_argument('file', type=argparse.FileType('r'))
args = parser.parse_args()
with args.file as file:
print file.read()
--- update ---
- - 更新 - -
Oh, @Wernight already said that in comments
哦，@Wernight 已经在评论中说过了
回答by Thomas Ahle
I'll just add the option to use pathlib:
我将添加使用选项pathlib：
import argparse, pathlib
parser = argparse.ArgumentParser()
parser.add_argument('file', type=pathlib.Path)
args = parser.parse_args()
with args.file.open('r') as file:
print(file.read())
