如何将字符串分成以“-”开头的部分？

Question

I have a python string like this:

str = "--jvm 100 --cpu 200"

How do I get two parts?

'--jvm 100'
'--cpu 200'

I used str.split('--') and got something that is not optimal:

'' 
'jvm 100'
'cpu 200'

I tried regex but can't figure it out.

Answer 1

Why not add those -- again

 input = "--jvm 100 --cpu 200"
 values = ["--%s" % item for item in input.split("--") if item]

Result: ['--jvm 100 ', '--cpu 200']

Answer 2

Assuming you're trying to get the values from all the arguments, you should use an argument parsing package to do this.

https://docs.python.org/2/howto/argparse.html

They're already designed with all the parsing rules so all you'd have to do is focus on getting values out of them. In many cases, arg parsing tools will let you specify how values should be typed, so numbers will be converted to integers and true/false converted to booleans.

import argparse

# tell our parser what args to expect and what type they are
parser = argparse.ArgumentParser()
parser.add_argument('--jvm', type=int)
parser.add_argument('--cpu', type=int)

raw = '--jvm 100 --cpu 200'
# argparser expects a list of args so split the string on spaces
args = parser.parse_args(raw.split())

# access our parsed args
print args.jvm
print args.cpu

The above is just an example, so you'll need to tune it to meet your needs.

Answer 3

使用正则表达式，您可以这样做：

re.findall(r'--.*?(?=\s+--|$)', str)

Answer 4

>>> import re
>>> re.findall(r'--\w+ \d+', str)
['--jvm 100', '--cpu 200']