Behave用戶自定義數據類型

在step句子中, 全部的參數默認是string類型, 若是用戶想使用複雜的或者其餘數據類型, 就須要瞭解如下bahave中的數據類型.

behave的數據類型轉換器是在parse和cfparse中支持.

parse模塊是string.format的逆函數.  parse_type是基於parse的擴展, 簡化了自定義數據類型的產生.

parse feature

• • 在類型轉換器中可選pattern
  • 函數描述符with_pattern()

parse_type feature

• • 簡化類型轉換器的生成
  • 基於cardinality建立類型轉換器
  • 提供擴展的解析器支持cardinality field
    

    Cardinality	Example	Description
    0..1	「{person:Person?}」	Zero or one: For optional parts.
    0..*	「{persons:Person*}」	Zero or more: For list<T> (many0).
    1..*	「{persons:Person+}」	One or more: For list<T> (many).

如何定義自定義數據類型

1. 用戶註冊一個數據類型, 例如在environment.py文件中
2. parse.Parse匹配string做爲一個數據類型, 而後它調用類型轉換器去轉換匹配的文本爲目標數據類型
   

   #普通的類型轉換
   from behave import register_type
   
   def parse_number(text):
       """
       Convert parsed text into a number.
       :param text: Parsed text, called by :py:meth:`parse.Parser.parse()`.
       :return: Number instance (integer), created from parsed text.
       """
       return int(text)
   # -- REGISTER: User-defined type converter (parse_type).
   register_type(Number=parse_number)
   
   #帶有正則的類型轉換
   @parse.with_pattern(r"a\s+")
   def parse_word_a(text):
       """Type converter for "a " (followed by one/more spaces)."""
       return text.strip()
   
   register_type(a_=parse_word_a)

parse中預約義的數據類型

http://jenisys.github.io/behave.example/datatype/builtin_types.html

Cardinality 0 or 1(optional)

#這個實現比上一個實現多了一步 TypeBuilder.with_optional(parse_word_a).
from behave import register_type
from parse_type import TypeBuilder
import parse

@parse.with_pattern(r"a\s+")
def parse_word_a(text):
    """Type converter for "a " (followed by one/more spaces)."""
    return text.strip()

# -- SAME:
# parse_optional_word_a = TypeBuilder.with_zero_or_one(parse_word_a)
parse_optional_word_a   = TypeBuilder.with_optional(parse_word_a)
register_type(optional_a_=parse_optional_word_a)

#step_impl中{:optional_a_}是一個可選項, 在step既能夠有"a "也能夠沒有
@when('attacked by {:optional_a_}{opponent}')
def step_attacked_by(context, a_, opponent):
    context.ninja_fight.opponent = opponent

 

Cardinality 1++

from behave import register_type
from parse_type import TypeBuilder

company_persons = [ "Alice", "Bob", "Charly", "Dodo" ]
parse_person = TypeBuilder.make_choice(company_persons)
register_type(Person=parse_person)

# -- MANY-TYPE: Persons := list<Person> with list-separator = "and"
# parse_persons = TypeBuilder.with_one_or_more(parse_person, listsep="and")
parse_persons = TypeBuilder.with_many(parse_person, listsep="and")
register_type(PersonAndMore=parse_persons)

# -- NEEDED-UNTIL: parse_type.cfparse.Parser is used by behave.
# parse_persons2 = TypeBuilder.with_many(parse_person)
# type_dict = {"Person+": parse_persons2}
# register_type(**type_dict)

 

　　Cardinality 0++

from behave import register_type
from parse_type import TypeBuilder

def slurp_space(text):
    return text
slurp_space.pattern = r"\s*"
register_type(slurp_space=slurp_space)

parse_color = TypeBuilder.make_choice([ "red", "green", "blue", "yellow" ])
register_type(Color=parse_color)

# -- MANY-TYPE: Persons := list<Person> with list-separator = "and"
# parse_colors = TypeBuilder.with_many0(parse_color, listsep="and")
parse_colors0A= TypeBuilder.with_zero_or_more(parse_color, listsep="and")
register_type(OptionalColorAndMore=parse_colors0A)