Question

我有多个脚本在调用python脚本（https://github.com/alvations/meanie）时给出一个数字列表作为参数来计算不同的方法：

例如，harmonic_mean()：

# -*- coding: utf-8 -*-

import math

def harmonic_mean(x): # x is a list of values.
  """ Returns the harmonic mean given a list of values. """
  return len(x) / sum([1/i for i in x])

def main(means):
  print "Input:", means
  means = map(float,means)
  print "harmonic mean = ", harmonic_mean(means)

if __name__ == '__main__':
  import sys
  if len(sys.argv) < 2:
    sys.stderr.write('Usage: python %s mean1 mean2 mean3 ... \n' % sys.argv[0])
    sys.exit(1)
  main(sys.argv[1:])

和root_mean_square()

# -*- coding: utf-8 -*-

import math

def root_mean_square(x): # x is a list of values.
  """ Returns the root mean square (rms) given a list of values. """
  return math.sqrt(sum([i*i for i in x])/len(x))

def main(means):
  print "Input:", means
  means = map(float,means)
  print "root mean square = ", root_mean_square(means)

if __name__ == '__main__':
  import sys
  if len(sys.argv) < 2:
    sys.stderr.write('Usage: python %s mean1 mean2 mean3 ... \n' % sys.argv[0])
    sys.exit(1)
  main(sys.argv[1:])

如您所见，这两个脚本完全相同，只是调用不同的mean()函数并在main()打印不同的输出。我如何组合它们并允许用户在控制台/终端上调用它时给出一个平均选项参数/参数？例如。组合脚本是调用meannie.py：

$ python meanie.py harmonic 1 2 3
$ python meanie.py hm 1 2 3

上面的命令应该提供与调用相同的输出（这就是用户现在调用harmonic_mean（）脚本的方式）：

$ python hm.py 1 2 3

Answer 1

Python具有一流的功能;他们像其他一切一样反对，可以用同样的方式传递。所以你只需要一种方法将用户输入映射到指定的函数，然后将其传递给main函数：

def harmonic_mean(x):
    ...

def root_mean_square(x):
    ...

MEAN_FUNCS_MAP = {
    'hm': harmonic_mean,
    'harmonic': harmonic_mean,
    'rms':  root_mean_square,
}

def main(mean_fn, means):
    print "Input:", means
    means = map(float,means)
    print "root mean square = ", mean_fn(means)    

if __name__ == '__main__':
    import sys
    if len(sys.argv) < 3 or sys.argv[1] not in MEAN_FUNCS_MAP:
        sys.stderr.write('Usage: python %s <function> <mean1> <mean2> <mean3> ... \n' % sys.argv[0])
        sys.exit(1)
    main( MEAN_FUNCS_MAP[sys.argv[1]], sys.argv[2:] )

您还应该查看argparse模块，它比滚动您自己的命令行界面更不容易出错。

如何通过参数化它们来组合python脚本？

1 个答案: