Local Configuration

Once you have Qiskit installed and running there are some optional configuration steps you can take to change the default behavior of Qiskit for your specific use case.

User Config File

The main location for local configuration of Qiskit is the user config file. This is an ini format file that can be used to change defaults in Qiskit.

For example:

[default]
circuit_drawer = mpl
circuit_mpl_style = default
package_warnings = False
transpile_optimization_level=3

By default this file lives in ~/.qiskit/settings.conf but the path used can be overriden with the QISKIT_SETTINGS environment variable. If QISKIT_SETTINGS is set its value will used as the path to the user config file.

Available options:

  • circuit_drawer: This is used to change the default backend for the circuit drawer qiskit.circuit.QuantumCircuit.draw() and qiskit.visualization.circuit_drawer(). It can be set to latex, mpl, text, or latex_source and when the ouptut kwarg is not explicitly set that drawer backend will be used.

  • circuit_mpl_style: This is the default style sheet used for the mpl output backend for the circuit drawer qiskit.circuit.QuantumCircuit.draw() and qiskit.visualization.circuit_drawer(). It can be set to default or bw.

  • package_warnings: This boolean flag when set to true will suppress the RuntimeWarnings normally raised when either qiskit-aer or qiskit-ibmq-provider can not be found.

  • transpile_optimization_level: This takes an integer between 0-3 and is used to change the default optimization level for transpile() and execute().

Environment Variables

There are also a few environment variables that can be set to alter the default behavior of Qiskit.

  • QISKIT_IN_PARALLEL: if this variable is set to something other than FALSE it will disable the use of multiprocessing to parallelize certain operations (for exapmle transpilation over multiple circuits) in Qiskit Terra.

  • QISKIT_SUPPRESS_PACKAGING_WARNINGS: When set to Y the RuntimeWarnings normally raised when either qiskit-aer or qiskit-ibmq-provider can not be found will be supressed.

  • QISKIT_IBMQ_PROVIDER_LOG_LEVEL: Specifies the log level to use, for the qiskit-ibmq-provider modules. If an invalid level is set, the log level defaults to WARNING. The valid log levels are DEBUG, INFO, WARNING, ERROR, and CRITICAL (case-insensitive). If the environment variable is not set, then the parent logger’s level is used, which also defaults to WARNING.

  • QISKIT_IBMQ_PROVIDER_LOG_FILE: Specifies the name of the log file to use from log messages originating from qiskit-ibmq-provider. If specified, messages will be logged to the file only. Otherwise messages will be logged to the standard error (usually the screen).

  • QISKIT_AQUA_MAX_GATES_PER_JOB: An optional parameter to set a threshold for splitting Aqua generated circuits up into multiple jobs submitted to a backend based on the number of gates.