marshmallow-sqlalchemy 给出语法错误

Question

在 python 3.5 中安装 marshmallow-sqlalchemy 后显示语法错误。

我已经使用以下命令安装了它 pip install marshmallow-sqlalchemy。

Traceback (most recent call last):
  File "run.py", line 1, in <module>
    from app import flask_app
  File "/var/www/html/mswipe-banner/mswipe-banner/app/__init__.py", line 10, in <module>
    from .models import *
  File "/var/www/html/mswipe-banner/mswipe-banner/app/models/__init__.py", line 1, in <module>
    from .banner import *
  File "/var/www/html/mswipe-banner/mswipe-banner/app/models/banner.py", line 1, in <module>
    from .base_model import *
  File "/var/www/html/mswipe-banner/mswipe-banner/app/models/base_model.py", line 1, in <module>
    from flask_marshmallow import Marshmallow
  File "/var/www/html/mswipe-banner/lib/python3.5/site-packages/flask_marshmallow/__init__.py", line 24, in <module>
    from . import sqla
  File "/var/www/html/mswipe-banner/lib/python3.5/site-packages/flask_marshmallow/sqla.py", line 13, in <module>
    import marshmallow_sqlalchemy as msqla
  File "/var/www/html/mswipe-banner/lib/python3.5/site-packages/marshmallow_sqlalchemy/__init__.py", line 1, in <module>
    from .schema import TableSchemaOpts, ModelSchemaOpts, TableSchema, ModelSchema
  File "/var/www/html/mswipe-banner/lib/python3.5/site-packages/marshmallow_sqlalchemy/schema.py", line 3, in <module>
    from .convert import ModelConverter
  File "/var/www/html/mswipe-banner/lib/python3.5/site-packages/marshmallow_sqlalchemy/convert.py", line 80
    ):
    ^
SyntaxError: invalid syntax

谢谢

Answer 1

安装失败，因为 marshmallow-sqlalchemy no longer supports Python 3.5。最后一个支持 Python 3.5 的版本是 18.0 版本，必须明确安装。

回溯中的特定错误是由 this 函数声明引起的：

def fields_for_model(
    self,
    model,
    *,
    include_fk=False,
    fields=None,
    exclude=None,
    base_fields=None,
    dict_cls=dict,
):

Python 3.6 包含一个 change 以允许在函数参数列表中使用尾随逗号。在此更改之前，这些签名是合法的：

>>> def f(a, b, c=1,):pass
... 
>>> def f(a, b, *, c=1):pass
... 
>>>

但这不是

>>> def f(a, b, *, c=1,):pass
  File "<stdin>", line 1
    def f(a, b, *, c=1,):pass
                       ^
SyntaxError: invalid syntax

参数列表中间的* - 表示关键字参数的开始 - 在版本18之后被添加到上面的marshmallow-sqlalchemy函数签名中，作为删除2.7过程的一部分和 3.5 兼容性。

marshmallow-sqlalchemy 给出语法错误

marshmallow-sqlalchemy giving syntax error

python

function-parameter

marshmallow

python-3.6