st.cache - 函数缓存装饰器

streamlit的cache装饰器用于记忆函数的历史执行。

方法原型

streamlit.cache(func=None, persist=False, allow_output_mutation=False, show_spinner=True, suppress_st_warning=False, **kwargs)

参数：

• func：要缓存的函数
• persist ：是否缓存到磁盘，布尔值
• allow_output_mutation：是否允许修改输出，布尔值
• show_spinner：是否显示执行状态，布尔值
• suppress_st_warning：是否抑制警告信息输出，布尔值

示例代码

>>> @st.cache
... def fetch_and_clean_data(url):
...     # Fetch data from URL here, and then clean it up.
...     return data
...
>>> d1 = fetch_and_clean_data(DATA_URL_1)
>>> # Actually executes the function, since this is the first time it was
>>> # encountered.
>>>
>>> d2 = fetch_and_clean_data(DATA_URL_1)
>>> # Does not execute the function. Just returns its previously computed
>>> # value. This means that now the data in d1 is the same as in d2.
>>>
>>> d3 = fetch_and_clean_data(DATA_URL_2)
>>> # This is a different URL, so the function executes.

下面的代码设置persist参数：

>>> @st.cache(persist=True)
... def fetch_and_clean_data(url):
...     # Fetch data from URL here, and then clean it up.
...     return data

要禁止哈希返回值，可以设置allow_output_mutation参数为True：

>>> @st.cache(allow_output_mutation=True)
... def fetch_and_clean_data(url):
...     # Fetch data from URL here, and then clean it up.
...     return data