Struct pyo3::types::PyTuple

source ·
#[repr(transparent)]
pub struct PyTuple(_);
Expand description

Represents a Python tuple object.

This type is immutable.

Implementations§

Constructs a new tuple with the given elements.

If you want to create a PyTuple with elements of different or unknown types, or from an iterable that doesn’t implement ExactSizeIterator, create a Rust tuple with the given elements and convert it at once using into_py.

Examples
use pyo3::prelude::*;
use pyo3::types::PyTuple;

Python::with_gil(|py| {
    let elements: Vec<i32> = vec![0, 1, 2, 3, 4, 5];
    let tuple: &PyTuple = PyTuple::new(py, elements);
    assert_eq!(format!("{:?}", tuple), "(0, 1, 2, 3, 4, 5)");
});
Panics

This function will panic if element’s ExactSizeIterator implementation is incorrect. All standard library structures implement this trait correctly, if they do, so calling this function using Vec<T> or &[T] will always succeed.

Constructs an empty tuple (on the Python side, a singleton object).

Gets the length of the tuple.

Checks if the tuple is empty.

Returns self cast as a PySequence.

Takes the slice self[low:high] and returns it as a new tuple.

Indices must be nonnegative, and out-of-range indices are clipped to self.len().

Gets the tuple item at the specified index.

Example
use pyo3::{prelude::*, types::PyTuple};

Python::with_gil(|py| -> PyResult<()> {
    let ob = (1, 2, 3).to_object(py);
    let tuple: &PyTuple = ob.downcast(py).unwrap();
    let obj = tuple.get_item(0);
    assert_eq!(obj.unwrap().extract::<i32>().unwrap(), 1);
    Ok(())
})
Available on neither Py_LIMITED_API nor PyPy.

Gets the tuple item at the specified index. Undefined behavior on bad index. Use with caution.

Safety

Caller must verify that the index is within the bounds of the tuple.

Available on non-Py_LIMITED_API only.

Returns self as a slice of objects.

Determines if self contains value.

This is equivalent to the Python expression value in self.

Returns the first index i for which self[i] == value.

This is equivalent to the Python expression self.index(value).

Returns an iterator over the tuple items.

Methods from Deref<Target = PyAny>§

Returns whether self and other point to the same object. To compare the equality of two objects (the == operator), use eq.

This is equivalent to the Python expression self is other.

Determines whether this object has the given attribute.

This is equivalent to the Python expression hasattr(self, attr_name).

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern attr_name.

Retrieves an attribute value.

This is equivalent to the Python expression self.attr_name.

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern attr_name.

Example: intern!ing the attribute name
#[pyfunction]
fn version(sys: &PyModule) -> PyResult<&PyAny> {
    sys.getattr(intern!(sys.py(), "version"))
}

Sets an attribute value.

This is equivalent to the Python expression self.attr_name = value.

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern name.

Example: intern!ing the attribute name
#[pyfunction]
fn set_answer(ob: &PyAny) -> PyResult<()> {
    ob.setattr(intern!(ob.py(), "answer"), 42)
}

Deletes an attribute.

This is equivalent to the Python statement del self.attr_name.

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern attr_name.

Returns an Ordering between self and other.

This is equivalent to the following Python code:

if self == other:
    return Equal
elif a < b:
    return Less
elif a > b:
    return Greater
else:
    raise TypeError("PyAny::compare(): All comparisons returned false")
Examples
use pyo3::prelude::*;
use pyo3::types::PyFloat;
use std::cmp::Ordering;

Python::with_gil(|py| -> PyResult<()> {
    let a = PyFloat::new(py, 0_f64);
    let b = PyFloat::new(py, 42_f64);
    assert_eq!(a.compare(b)?, Ordering::Less);
    Ok(())
})?;

It will return PyErr for values that cannot be compared:

use pyo3::prelude::*;
use pyo3::types::{PyFloat, PyString};

Python::with_gil(|py| -> PyResult<()> {
    let a = PyFloat::new(py, 0_f64);
    let b = PyString::new(py, "zero");
    assert!(a.compare(b).is_err());
    Ok(())
})?;

Tests whether two Python objects obey a given CompareOp.

lt, le, eq, ne, gt and ge are the specialized versions of this function.

Depending on the value of compare_op, this is equivalent to one of the following Python expressions:

compare_opPython expression
CompareOp::Eqself == other
CompareOp::Neself != other
CompareOp::Ltself < other
CompareOp::Leself <= other
CompareOp::Gtself > other
CompareOp::Geself >= other
Examples
use pyo3::class::basic::CompareOp;
use pyo3::prelude::*;
use pyo3::types::PyInt;

Python::with_gil(|py| -> PyResult<()> {
    let a: &PyInt = 0_u8.into_py(py).into_ref(py).downcast()?;
    let b: &PyInt = 42_u8.into_py(py).into_ref(py).downcast()?;
    assert!(a.rich_compare(b, CompareOp::Le)?.is_true()?);
    Ok(())
})?;

Tests whether this object is less than another.

This is equivalent to the Python expression self < other.

Tests whether this object is less than or equal to another.

This is equivalent to the Python expression self <= other.

Tests whether this object is equal to another.

This is equivalent to the Python expression self == other.

Tests whether this object is not equal to another.

This is equivalent to the Python expression self != other.

Tests whether this object is greater than another.

This is equivalent to the Python expression self > other.

Tests whether this object is greater than or equal to another.

This is equivalent to the Python expression self >= other.

Determines whether this object appears callable.

This is equivalent to Python’s callable() function.

Examples
use pyo3::prelude::*;

Python::with_gil(|py| -> PyResult<()> {
    let builtins = PyModule::import(py, "builtins")?;
    let print = builtins.getattr("print")?;
    assert!(print.is_callable());
    Ok(())
})?;

This is equivalent to the Python statement assert callable(print).

Note that unless an API needs to distinguish between callable and non-callable objects, there is no point in checking for callability. Instead, it is better to just do the call and handle potential exceptions.

Calls the object.

This is equivalent to the Python expression self(*args, **kwargs).

Examples
use pyo3::prelude::*;
use pyo3::types::PyDict;

const CODE: &str = r#"
def function(*args, **kwargs):
    assert args == ("hello",)
    assert kwargs == {"cruel": "world"}
    return "called with args and kwargs"
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let fun = module.getattr("function")?;
    let args = ("hello",);
    let kwargs = PyDict::new(py);
    kwargs.set_item("cruel", "world")?;
    let result = fun.call(args, Some(kwargs))?;
    assert_eq!(result.extract::<&str>()?, "called with args and kwargs");
    Ok(())
})

Calls the object without arguments.

This is equivalent to the Python expression self().

Examples
use pyo3::prelude::*;

Python::with_gil(|py| -> PyResult<()> {
    let module = PyModule::import(py, "builtins")?;
    let help = module.getattr("help")?;
    help.call0()?;
    Ok(())
})?;

This is equivalent to the Python expression help().

Calls the object with only positional arguments.

This is equivalent to the Python expression self(*args).

Examples
use pyo3::prelude::*;

const CODE: &str = r#"
def function(*args, **kwargs):
    assert args == ("hello",)
    assert kwargs == {}
    return "called with args"
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let fun = module.getattr("function")?;
    let args = ("hello",);
    let result = fun.call1(args)?;
    assert_eq!(result.extract::<&str>()?, "called with args");
    Ok(())
})

Calls a method on the object.

This is equivalent to the Python expression self.name(*args, **kwargs).

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern name.

Examples
use pyo3::prelude::*;
use pyo3::types::PyDict;

const CODE: &str = r#"
class A:
    def method(self, *args, **kwargs):
        assert args == ("hello",)
        assert kwargs == {"cruel": "world"}
        return "called with args and kwargs"
a = A()
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let instance = module.getattr("a")?;
    let args = ("hello",);
    let kwargs = PyDict::new(py);
    kwargs.set_item("cruel", "world")?;
    let result = instance.call_method("method", args, Some(kwargs))?;
    assert_eq!(result.extract::<&str>()?, "called with args and kwargs");
    Ok(())
})

Calls a method on the object without arguments.

This is equivalent to the Python expression self.name().

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern name.

Examples
use pyo3::prelude::*;

const CODE: &str = r#"
class A:
    def method(self, *args, **kwargs):
        assert args == ()
        assert kwargs == {}
        return "called with no arguments"
a = A()
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let instance = module.getattr("a")?;
    let result = instance.call_method0("method")?;
    assert_eq!(result.extract::<&str>()?, "called with no arguments");
    Ok(())
})

Calls a method on the object with only positional arguments.

This is equivalent to the Python expression self.name(*args).

To avoid repeated temporary allocations of Python strings, the intern! macro can be used to intern name.

Examples
use pyo3::prelude::*;

const CODE: &str = r#"
class A:
    def method(self, *args, **kwargs):
        assert args == ("hello",)
        assert kwargs == {}
        return "called with args"
a = A()
"#;

Python::with_gil(|py| {
    let module = PyModule::from_code(py, CODE, "", "")?;
    let instance = module.getattr("a")?;
    let args = ("hello",);
    let result = instance.call_method1("method", args)?;
    assert_eq!(result.extract::<&str>()?, "called with args");
    Ok(())
})

Returns whether the object is considered to be true.

This is equivalent to the Python expression bool(self).

Returns whether the object is considered to be None.

This is equivalent to the Python expression self is None.

Returns whether the object is Ellipsis, e.g. ....

This is equivalent to the Python expression self is ....

Returns true if the sequence or mapping has a length of 0.

This is equivalent to the Python expression len(self) == 0.

Gets an item from the collection.

This is equivalent to the Python expression self[key].

Sets a collection item value.

This is equivalent to the Python expression self[key] = value.

Deletes an item from the collection.

This is equivalent to the Python expression del self[key].

Takes an object and returns an iterator for it.

This is typically a new iterator but if the argument is an iterator, this returns itself.

Returns the Python type object for this object’s type.

Returns the Python type pointer for this object.

👎Deprecated since 0.18.0: use the equivalent .downcast()

Converts this PyAny to a concrete Python type.

Downcast this PyAny to a concrete Python type or pyclass.

Note that you can often avoid downcasting yourself by just specifying the desired type in function or method signatures. However, manual downcasting is sometimes necessary.

For extracting a Rust-only type, see PyAny::extract.

Example: Downcasting to a specific Python object
use pyo3::prelude::*;
use pyo3::types::{PyAny, PyDict, PyList};

Python::with_gil(|py| {
    let dict = PyDict::new(py);
    assert!(dict.is_instance_of::<PyAny>().unwrap());
    let any: &PyAny = dict.as_ref();

    assert!(any.downcast::<PyDict>().is_ok());
    assert!(any.downcast::<PyList>().is_err());
});
Example: Getting a reference to a pyclass

This is useful if you want to mutate a PyObject that might actually be a pyclass.

use pyo3::prelude::*;

#[pyclass]
struct Class {
    i: i32,
}

Python::with_gil(|py| {
    let class: &PyAny = Py::new(py, Class { i: 0 }).unwrap().into_ref(py);

    let class_cell: &PyCell<Class> = class.downcast()?;

    class_cell.borrow_mut().i += 1;

    // Alternatively you can get a `PyRefMut` directly
    let class_ref: PyRefMut<'_, Class> = class.extract()?;
    assert_eq!(class_ref.i, 1);
    Ok(())
})

Converts this PyAny to a concrete Python type without checking validity.

Safety

Callers must ensure that the type is valid or risk type confusion.

Extracts some type from the Python object.

This is a wrapper function around FromPyObject::extract().

Returns the reference count for the Python object.

Computes the “repr” representation of self.

This is equivalent to the Python expression repr(self).

Computes the “str” representation of self.

This is equivalent to the Python expression str(self).

Retrieves the hash code of self.

This is equivalent to the Python expression hash(self).

Returns the length of the sequence or mapping.

This is equivalent to the Python expression len(self).

Returns the list of attributes of this object.

This is equivalent to the Python expression dir(self).

Checks whether this object is an instance of type ty.

This is equivalent to the Python expression isinstance(self, ty).

Checks whether this object is an instance of type T.

This is equivalent to the Python expression isinstance(self, T), if the type T is known at compile time.

Determines if self contains value.

This is equivalent to the Python expression value in self.

Returns a GIL marker constrained to the lifetime of this type.

Available on non-PyPy only.

Return a proxy object that delegates method calls to a parent or sibling class of type.

This is equivalent to the Python expression super()

Trait Implementations§

Gets the underlying FFI pointer, returns a borrowed pointer.

Converts this type into a shared reference of the (usually inferred) input type.
Formats the value using the given formatter. Read more
The resulting type after dereferencing.
Dereferences the value.
Formats the value using the given formatter. Read more
Converts to this type from the input type.
Converts to this type from the input type.
Extracts Self from the source PyObject.
Available on crate feature experimental-inspect only.
Extracts the type hint information for this type when it appears as an argument. Read more
The returned type after indexing.
Performs the indexing (container[index]) operation. Read more
The returned type after indexing.
Performs the indexing (container[index]) operation. Read more
The returned type after indexing.
Performs the indexing (container[index]) operation. Read more
The returned type after indexing.
Performs the indexing (container[index]) operation. Read more
The returned type after indexing.
Performs the indexing (container[index]) operation. Read more
The returned type after indexing.
Performs the indexing (container[index]) operation. Read more
The returned type after indexing.
Performs the indexing (container[index]) operation. Read more
The type of the elements being iterated over.
Which kind of iterator are we turning this into?
Creates an iterator from a value. Read more
Performs the conversion.
Available on crate feature experimental-inspect only.
Extracts the type hint information for this type when it appears as a return value. Read more
Returns a GIL marker constrained to the lifetime of this type.
Cast &PyAny to &Self without no type checking. Read more
Utility type to make Py::as_ref work.
Class name.
Module name, if any.
Returns the PyTypeObject instance for this type.
Checks if object is an instance of this type or a subclass of this type.
Returns the safe abstraction over the type object.
Checks if object is an instance of this type.
Converts self into a Python object.

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Convert from an arbitrary PyObject. Read more
Convert from an arbitrary borrowed PyObject. Read more
Convert from an arbitrary PyObject or panic. Read more
Convert from an arbitrary PyObject or panic. Read more
Convert from an arbitrary PyObject. Read more
Convert from an arbitrary borrowed PyObject. Read more
Convert from an arbitrary borrowed PyObject. Read more
Convert from an arbitrary borrowed PyObject. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Cast from a concrete Python object type to PyObject.
Cast from a concrete Python object type to PyObject. With exact type check.
Cast a PyAny to a specific type of PyObject. The caller must have already verified the reference is for this type. Read more
👎Deprecated since 0.17.0: this trait is no longer used by PyO3, use ToPyObject or IntoPy<PyObject>
Converts self into a Python object and calls the specified closure on the native FFI pointer underlying the Python object. Read more
Converts the given value to a String. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.