The following simplified example shows you how you can pass multiple [pscustomobject] ([psobject]) instances from PowerShell to a Python script (passed as a string via -c in this case):
by using JSON as the serialization format, via
ConvertTo-Json...... and passing that JSON via the pipeline, which Python can read via stdin (standard input).
Important:
Character encoding:
PowerShell uses the encoding specified in the
$OutputEncodingpreference variable when sending data to external programs (such as Python), which commendably defaults to BOM-less UTF-8 in PowerShell [Core] v6+, but regrettably to ASCII(!) in Windows PowerShell.Just like PowerShell limits you to sending text to an external program, it also invariably interprets what it receives as text, namely based on the encoding stored in
[Console]::OutputEncoding; regrettably, both PowerShell editions as of this writing default to the system's OEM code page.To both send and receive (BOM-less) UTF-8 in both PowerShell editions, (temporarily) set
$OutputEncodingand[Console]::OutputEncodingas follows:
$OutputEncoding = [Console]::OutputEncoding = [System.Text.Utf8Encoding]::new($false)
If you want your Python script to also output objects, again consider using JSON, which on the PowerShell you can parse into objects with
ConvertFrom-Json.
# Sample input objects.
$data = [pscustomobject] @{ one = 1; two = 2 }, [pscustomobject] @{ one = 10; two = 20 }
# Convert to JSON and pipe to Python.
ConvertTo-Json $data | python -c @'
import sys, json
# Parse the JSON passed via stdin into a list of dictionaries.
dicts = json.load(sys.stdin)
# Sample processing: print the 'one' entry of each dict.
for dict in dicts:
print(dict['one'])
'@
If the data to pass is a collection of single-line strings, you don't need JSON:
$data = 'foo', 'bar', 'baz'
$data | python -c @'
import sys
# Sample processing: print each stdin input line enclosed in [...]
for line in sys.stdin:
print('[' + line.rstrip('\r\n') + ']')
'@