关于python：忽略def如果没有使用？

ignore a def if not in use?

我有下面的剧本-

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import os, errno
import argparse

def removecompressed(filename):
try:
os.remove(filename)
print('Removing {}'.format(args.compressedfile))
except OSError as e: # this would be"except OSError, e:" before Python 2.6
print ('File {} does not exist in location {}!'.format(args.compressedfile, args.localpath))
if e.errno != errno.ENOENT: # errno.ENOENT = no such file or directory
raise # re-raise exception if a different error occured

def removeencrypted(filename):
try:
os.remove(filename)
print('Removing {}'.format(args.encryptedfile))
except OSError as e: # this would be"except OSError, e:" before Python 2.6
print ('File {} does not exist in location {}!'.format(args.encryptedfile, args.localpath))
if e.errno != errno.ENOENT: # errno.ENOENT = no such file or directory
raise # re-raise exception if a different error occured

parser = argparse.ArgumentParser()
parser.add_argument('-p', '--localpath', type=str, default='', help="the path containing the files")
parser.add_argument('-c', '--compressedfile', type=str, default='', help="the compressed file to be deleted")
parser.add_argument('-e', '--encryptedfile', type=str, default='', help="the encrypted file to be deleted")
args = parser.parse_args()

removecompressed(args.localpath + args.compressedfile)
removeencrypted(args.localpath + args.encryptedfile)

但我希望-e和-c参数是可选的。我该怎么做呢？

我理解此回复：argparse可选位置参数？

但问题是，def首先将两个字符串一起解析以生成文件名。如果我删除其中一个参数，它会抱怨添加了一个字符串和一个none值。

编辑-如果我使用所有3个参数，没有问题。例如，如果我删除了-e或-c，我就删除了-e，得到以下异常-

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Traceback (most recent call last):
File"cleanup.py", line 35, in <module>
removeencrypted(args.localpath + args.encryptedfile)
TypeError: Can't convert 'NoneType' object to str implicitly

我已更新参数以包含默认值='