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 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().