set environment variable

Author: szabgab

sites/en/pages/setting-environment-variables.txt

@@ -0,0 +1,38 @@
+=title Setting environment variables on the command line on Windows, Linux, macOS
+=timestamp 2025-04-26T07:30:01
+=indexes set, ENV
+=status show
+=author szabgab
+=archive 1
+=comments_disqus_enable 0
+=show_related 1
+
+Setting an environment variable on Linux and macOS can be done before we run some program.
+
+```
+$ python -c 'import os; print(os.getenv("NAME"))'
+None
+
+$ NAME=Foo python -c 'import os; print(os.getenv("NAME"))'
+Foo
+```
+
+
+On Windows we need to do it separately:
+
+In CMD:
+
+```
+> set NAME=Foo
+> python -c "import os; print(os.getenv('NAME'))"
+Foo
+```
+
+In PowerShell
+
+
+```
+> [Environment]::SetEnvironmentVariable("NAME", "Foo", "Process")
+> python -c "import os; print(os.getenv('NAME'))"
+Foo
+```