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os.getenv

The os.getenv function reads an environment variable from the environment used by exec.run. Use it in standalone scripts and script steps to access inherited values without launching a subprocess.

Usage​

os.getenv(name, default = None)

Arguments​

name
Required. A nonempty environment variable name as a string, without = or null bytes.
default
(Optional) The value returned when the variable is absent. Defaults to None.

Returns​

The variable's string value when present, including "" for an explicitly empty variable; otherwise default. Names are case-insensitive on Windows and case-sensitive on other platforms.

The lookup uses the script's effective execution environment, including applicable authentication, command, and step settings, plus changes made with os.setenv. The PATH value includes tools added by dependencies.tools. A per-call env override on exec.run or component.exec applies only to that call and does not change later lookups.

The env dictionary remains the read-only collection of explicitly declared step inputs. It is still empty in a standalone script. Neither API changes the process environment.

Examples​

Read a value with a fallback​

region = os.getenv("AWS_REGION", "us-east-1")

Pass a secret through standard input​

token = os.getenv("TOKEN")
if token == None:
    fail("TOKEN is required")
exec.run(["some-tool", "--token-stdin"], stdin = token, output = "capture")

Related​

  • os.environ returns a frozen snapshot of all execution variables.

  • os.setenv changes a variable within this script invocation.

  • exec.run accepts input and environment overrides for one command.

  • env exposes declared step inputs.

  • exec.which finds programs in the same execution environment.