python.snippets

global !p
def fb(string, c=0):
    '''Count brackets'''
    left_bracket = string.find("(")
    if left_bracket > -1:
        string = string[left_bracket + 1:]
        right_bracket = string.find(")")
        if right_bracket > -1:
            if string[:right_bracket].find("(") == -1:
                c += 1
            string = string[right_bracket + 1:]
        return fb(string, c)
    else:
        return c

def check_regexp_for_params(snip, t):
    if len(t[1]):
        arg_count = fb(t[1])
        if arg_count:
            args = ", ".join( ["arg%d" % (x+1) for x in range(arg_count)] )
            snip.rv = ', ' + args
endglobal

snippet st "Lettuce step decorated function" b
@step(r"${1}")
def ${2:step_name}(step${3:`!p check_regexp_for_params(snip, t)`}):
    ${4:pass}
endsnippet