使用argparse在python中将csv转换为xml

Question

一个非常快速的问题，基本上我的程序采用一个输入文件，这是一个csv文件，然后将其转换为一个xml文件。但是，xml文件的名称可以由用户输入设置，或者如果用户未指定名称，则xml文件将与csv文件具有相同的名称，但扩展名为.xml。我需要帮助后者。到目前为止，我的程序在输出文件被赋予名称但我不知道如何在用户没有输入名称时设置xml文件名时起作用。我知道如果用户没有设置名称，那么argparse.outputfile是none，我可以编写一个简单的if语句进行检查，但我不知道如何将名称设置为与之后的csv文件名相同。这是我的代码：

import sys, argparse
import csv
import indent
from xml.etree.ElementTree import ElementTree, Element, SubElement, Comment, tostring

parser=argparse.ArgumentParser(description='Convert wordlist text files to various formats.', prog='Text Converter')
parser.add_argument('-v','--verbose',action='store_true',dest='verbose',help='Increases messages being printed to stdout')
parser.add_argument('-c','--csv',action='store_true',dest='readcsv',help='Reads CSV file and converts to XML file with same name')
parser.add_argument('-x','--xml',action='store_true',dest='toxml',help='Convert CSV to XML with different name')
parser.add_argument('-i','--inputfile',type=argparse.FileType('r'),dest='inputfile',help='Name of file to be imported',required=True)
parser.add_argument('-o','--outputfile',type=argparse.FileType('w'),dest='outputfile',help='Output file name')
args = parser.parse_args()

def main(argv):
    reader = read_csv(args.inputfile)
    if args.verbose: 
        print ('Verbose Selected')
    if args.toxml:
        if args.verbose:
            print ('Convert to XML Selected')
        generate_xml(reader, args.outputfile)
    if args.readcsv:
        if args.verbose:
            print ('Reading CSV file')
    if not (args.toxml or args.readcsv):
        parser.error('No action requested')
    return 1

def read_csv(inputfile):
      return list(csv.reader(inputfile))

def generate_xml(reader,outfile):
    root = Element('Solution')
    root.set('version','1.0')
    tree = ElementTree(root)

    head = SubElement(root, 'DrillHoles')
    head.set('total_holes', '238')

    description = SubElement(head,'description')
    current_group = None
    i = 0
    for row in reader:
        if i > 0:
            x1,y1,z1,x2,y2,z2,cost = row
            if current_group is None or i != current_group.text:
                current_group = SubElement(description, 'hole',{'hole_id':"%s"%i})

                collar = SubElement (current_group, 'collar',{'':', '.join((x1,y1,z1))}),
                toe = SubElement (current_group, 'toe',{'':', '.join((x2,y2,z2))})                                       
                cost = SubElement(current_group, 'cost',{'':cost})
        i+=1    
    indent.indent(root)
    tree.write(outfile)

if (__name__ == "__main__"):
    sys.exit(main(sys.argv))

Answer 1

将“import os”添加到文件顶部的导入列表中。然后，在解析之后，您可以检查并设置参数：

if args.outputfile is None:
    args.outputfile = os.path.splitext(args.inputfile)[0] + '.xml'

顺便说一句，参数默认为长选项名称。如果要使用其他名称，则只需要“dest”关键字。因此，例如，'verbose'可以是：

parser.add_argument('-v', '--verbose', action='store_true',
    help='Increases messages being printed to stdout')

编辑：这是使用输出文件处理重新编写的示例，以及使用chepner建议使用文件名的位置参数。

import os
import sys
import argparse
import csv
import indent
from xml.etree.ElementTree import ElementTree, Element, SubElement, Comment, tostring

def get_args(args):
    parser=argparse.ArgumentParser(description='Convert wordlist text files to various formats.', prog='Text Converter')
    parser.add_argument('-v','--verbose',action='store_true',dest='verbose',help='Increases messages being printed to stdout')
    parser.add_argument('-c','--csv',action='store_true',dest='readcsv',help='Reads CSV file and converts to XML file with same name')
    parser.add_argument('-x','--xml',action='store_true',dest='toxml',help='Convert CSV to XML with different name')
    #parser.add_argument('-i','--inputfile',type=str,help='Name of file to be imported',required=True)
    #parser.add_argument('-o','--outputfile',help='Output file name')
    parser.add_argument('inputfile',type=str,help='Name of file to be imported')
    parser.add_argument('outputfile',help='(optional) Output file name',nargs='?')
    args = parser.parse_args()
    if not (args.toxml or args.readcsv):
        parser.error('No action requested')
        return None
    if args.outputfile is None:
        args.outputfile = os.path.splitext(args.inputfile)[0] + '.xml'
    return args

def main(argv):
    args = get_args(argv[1:])
    if args is None:
        return 1
    inputfile = open(args.inputfile, 'r')
    outputfile = open(args.outputfile, 'w')
    reader = read_csv(inputfile)
    if args.verbose:
        print ('Verbose Selected')
    if args.toxml:
        if args.verbose:
            print ('Convert to XML Selected')
        generate_xml(reader, outputfile)
    if args.readcsv:
        if args.verbose:
            print ('Reading CSV file')
    return 1 # you probably want to return 0 on success

def read_csv(inputfile):
      return list(csv.reader(inputfile))

def generate_xml(reader,outfile):
    root = Element('Solution')
    root.set('version','1.0')
    tree = ElementTree(root)

    head = SubElement(root, 'DrillHoles')
    head.set('total_holes', '238')

    description = SubElement(head,'description')
    current_group = None
    i = 0
    for row in reader:
        if i > 0:
            x1,y1,z1,x2,y2,z2,cost = row
            if current_group is None or i != current_group.text:
                current_group = SubElement(description, 'hole',{'hole_id':"%s"%i})

                collar = SubElement (current_group, 'collar',{'':', '.join((x1,y1,z1))}),
                toe = SubElement (current_group, 'toe',{'':', '.join((x2,y2,z2))})
                cost = SubElement(current_group, 'cost',{'':cost})
        i+=1
    indent.indent(root)
    tree.write(outfile)

if (__name__ == "__main__"):
    sys.exit(main(sys.argv))