无法通过命令行传递值

Question

我必须编写一个程序来读取文件并将一些分析写入文本文件。该程序必须通过命令行获取一些信息，但我看不到，即使给定模板也无法弄清楚。我写了一个测试程序，看看我是否可以成功地将命令行输入传递给 class.

#!/usr/bin/env python3

########################################################################
# CommandLine
########################################################################
class CommandLine() :
    '''
    Handle the command line, usage and help requests.

    CommandLine uses argparse, now standard in 2.7 and beyond. 
    it implements a standard command line argument parser with various argument options,
    a standard usage and help, and an error termination mechanism do-usage_and_die.

    attributes:
    all arguments received from the commandline using .add_argument will be
    avalable within the .args attribute of object instantiated from CommandLine.
    For example, if myCommandLine is an object of the class, and requiredbool was
    set as an option using add_argument, then myCommandLine.args.requiredbool will
    name that option.

    '''

    def __init__(self, inOpts=None) :
        '''
        CommandLine constructor.
        Implements a parser to interpret the command line argv string using argparse.
        '''

        import argparse
        self.parser = argparse.ArgumentParser(description = 'Program prolog - a brief description of what this thing does', 
                                             epilog = 'Program epilog - some other stuff you feel compelled to say', 
                                             add_help = True, #default is True 
                                             prefix_chars = '-', 
                                             usage = '%(prog)s [options] -option1[default] <input >output'
                                             )
        self.parser.add_argument('inFile', action = 'store', help='input file name')
        self.parser.add_argument('outFile', action = 'store', help='output file name') 
        self.parser.add_argument('-lG', '--longestGene', action = 'store', nargs='?', const=True, default=True, help='longest Gene in an ORF')
        self.parser.add_argument('-mG', '--minGene', type=int, choices= range(0, 2000), action = 'store', help='minimum Gene length')
        self.parser.add_argument('-s', '--start', action = 'append', nargs='?', help='start Codon') #allows multiple list options
        self.parser.add_argument('-v', '--version', action='version', version='%(prog)s 0.1')  
        if inOpts is None :
            self.args = self.parser.parse_args()
        else :
            self.args = self.parser.parse_args(inOpts)

########################################################################
#MAIN GOES HERE
########################################################################


def main(myCommandLine=None):
    '''
    Implements the Usage exception handler that can be raised from anywhere in process.  

    '''

    myCommandLine = CommandLine(myCommandLine)

        #myCommandLine.args.inFile #has the input file name
        #myCommandLine.args.outFile #has the output file name
        #myCommandLine.args.longestGene #is True if only the longest Gene is desired
        #myCommandLine.args.start #is a list of start codons
        #myCommandLine.args.minGene #is the minimum Gene length to include

    print (myCommandLine.args) # print the parsed argument string .. as there is nothing better to do

    if myCommandLine.args.longestGene:
        print ('longestGene is', str(myCommandLine.args.longestGene) )
    else :
        pass
    class Test:
        def __init__(self):
            print(myCommandLine.args.minGene)

if __name__ == "__main__":
    main()

class Test:
    def __init__(self):
        self.test()

    def test(self, infile = myCommandLine.args.inFile, outfile = myCommandLine.args.outFile, longest = myCommandLine.args.longestGene, start = myCommandLine.args.start, min = myCommandLine.args.minGene):
        print(infile)
        print(outfile)
        print(longest)
        print(start)
        print(min)

new_obj = Test()

命令行输入应如下所示：python testcommand.py -minG 100 -longestG -starts ATG tass2ORFdata-ATG-100.txt

据说主程序会按照它所说的 "MAIN GOES HERE" 但是当我尝试这样做时，我得到了 "myCommandline is not defined" 的错误。所以我把程序移到了最后。但是我收到错误 'the '>' operator is reserved for future use"

如果重要的话，我正在使用 Powershell。如何将此数据输入我的 class？

Answer 1

您不需要 CommandLine class。正如 James Mills 所建议的，这里有一个例子：

import argparse

class Test:
    def __init__(self, infile, outfile, longest, start, min):
        self.infile = infile
        self.test()

    def test(self):
        print(self.infile)

def main():
    parser = argparse.ArgumentParser(description = 'Program prolog', 
                                     epilog = 'Program epilog', 
                                     add_help = True, #default is True 
                                     prefix_chars = '-', 
                                     usage = 'xxx')
    parser.add_argument('-i', '--inFile', action = 'store', help='input file name')
    parser.add_argument('-o', '--outFile', action = 'store', help='output file name') 
    parser.add_argument('-lG', '--longestGene', action = 'store', nargs='?', const=True, default=True, help='longest Gene in an ORF')
    parser.add_argument('-mG', '--minGene', type=int, choices= range(0, 20), action = 'store', help='minimum Gene length')
    parser.add_argument('-s', '--start', action = 'append', nargs='?', help='start Codon') #allows multiple list options
    parser.add_argument('-v', '--version', action='version', version='%(prog)s 0.1')  
    args = parser.parse_args()
    test = Test(args.inFile, args.outFile, args.longestGene, args.minGene, args.start)

if __name__ == '__main__':
    main()

无法通过命令行传递值

Can't pass values via command line

python

powershell

command-line

python-3.x