Behave用户自定义数据类型

在step句子中, 所有的参数默认是string类型, 如果用户想使用复杂的或者其他数据类型, 就需要了解以下bahave中的数据类型.

behave的数据类型转换器是在parse和cfparse中支持.

parse模块是string.format的逆函数. parse_type是基于parse的扩展, 简化了自定义数据类型的产生.

parse feature

- 在类型转换器中可选pattern
- 函数描述符with_pattern()

parse_type feature

简化类型转换器的生成
基于cardinality创建类型转换器

提供扩展的解析器支持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).

如何定义自定义数据类型

用户注册一个数据类型, 例如在environment.py文件中

parse.Parse匹配string作为一个数据类型, 然后它调用类型转换器去转换匹配的文本为目标数据类型

#普通的类型转换
from behave import register_typedef 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)#带有正则的类型转换
@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中预定义的数据类型

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

Cardinality 0 or 1(optional)

#这个实现比上一个实现多了一步 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_}是一个可选项, 在step既可以有"a "也可以没有
@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 TypeBuildercompany_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 TypeBuilderdef 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)