60 lines
1.9 KiB
Plaintext
60 lines
1.9 KiB
Plaintext
---
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title: parallel_map
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description: API reference for qiskit.tools.parallel_map
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in_page_toc_min_heading_level: 1
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python_api_type: function
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python_api_name: qiskit.tools.parallel_map
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---
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# qiskit.tools.parallel\_map
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<Function id="qiskit.tools.parallel_map" isDedicatedPage={true} github="https://github.com/qiskit/qiskit/tree/stable/0.23/qiskit/tools/parallel.py" signature="parallel_map(task, values, task_args=(), task_kwargs={}, num_processes=2)">
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Parallel execution of a mapping of values to the function task. This is functionally equivalent to:
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```python
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result = [task(value, *task_args, **task_kwargs) for value in values]
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```
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On Windows this function defaults to a serial implementation to avoid the overhead from spawning processes in Windows.
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**Parameters**
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* **task** (*func*) – Function that is to be called for each value in `values`.
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* **values** (*array\_like*) – List or array of values for which the `task` function is to be evaluated.
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* **task\_args** (*list*) – Optional additional arguments to the `task` function.
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* **task\_kwargs** (*dict*) – Optional additional keyword argument to the `task` function.
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* **num\_processes** (*int*) – Number of processes to spawn.
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**Returns**
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**The result list contains the value of**
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**`task(value, *task_args, **task_kwargs)` for**
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each value in `values`.
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**Return type**
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result
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**Raises**
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**QiskitError** – If user interrupts via keyboard.
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## Events:
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terra.parallel.start: The collection of parallel tasks are about to start. terra.parallel.update: One of the parallel task has finished. terra.parallel.finish: All the parallel tasks have finished.
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**Examples**
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```python
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import time
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from qiskit.tools.parallel import parallel_map
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def func(_):
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time.sleep(0.1)
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return 0
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parallel_map(func, list(range(10)));
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```
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</Function>
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