Built-in strategies¶

This page shows some of the strategies that Hypothesis provides for you.

Strategies provided by Hypothesis¶

Here is a selection of strategies provided by Hypothesis that may be useful to know:

integers(). Generates integers.
floats(). Generates floats.
booleans(). Generates booleans.
text(). Generates unicode strings (i.e., instances of python:str).
lists(). Generates lists with elements from the strategy passed to it. st.lists(st.integers()) generates lists of integers.
tuples(). Generates tuples of a fixed length. st.tuples(st.integers(), st.floats()) generates tuples with two elements, where the first element is an integer and the second is a float.
one_of(). Generates from any of the strategies passed to it. st.one_of(st.integers(), st.floats()) generates either integers or floats. You can also use | to construct one_of(), like st.integers() | st.floats().
builds(). Generates instances of a class (or other callable) by specifying a strategy for each argument. st.builds(Person, name=st.text(), age=st.integers()).
just(). Generates the exact value passed to it. st.just("a") generates the exact string "a". This is useful when something expects to be passed a strategy. For instance, st.lists(st.integers() | st.just("a")) generates lists whose elements are either integers or the string "a".
sampled_from(). Generates a random value from a list. st.sampled_from(["a", 1, True]) is equivalent to st.just("a") | st.just(1) | st.just(True).
none(). Generates None. Useful for parameters that can be optional, like st.integers() | st.none().