Quickstart: Python

Build a working study in Python in a few minutes. For the full API, see the Python SDK reference.

Install psycloudpy

# From the PsyCloud monorepo (not yet on PyPI)
pip install -e packages/psycloudpy

Write a study

Save this as stroop.py. It builds a minimal Stroop task — two factors, a fixation, and a keypress response — and writes a runnable bundle.

stroop.py

from psycloudpy import experiment, text, keypress, pc_bundle_write
from psycloudpy.expr import col
 
bundle = (
    experiment(id="hello.stroop", name="Hello Stroop")
    .phase("main", label="Trials")
    .factors(word=["red", "blue"], ink=["red", "blue"])
    .cross()
    .shuffle()
    .screen("trial")
    .present(text("+"), 250)
    .ask(text(col.word, fill=col.ink, font_size=72), keypress(keys=["r", "b"]))
    .bind_self("word", "ink")
    .bundle(with_auto_ids=True)
)
 
pc_bundle_write(bundle, "stroop_bundle", overwrite=True)

Generate the bundle
```
python stroop.py
```
This writes a stroop_bundle/ directory containing the bundle artifacts.
Run or edit it
Compile or serve the bundle with the CLI, or open it in Studio via New Study → Import bundle to keep editing visually.
```
psycloud validate ./stroop_bundle
psycloud compile  ./stroop_bundle --out ./dist/bundle.json
```

Dynamic values

col.word and col.ink bind each trial's values into the screen. The expression DSL covers conditionals, derived columns, and response-based logic.

Quickstart: Python

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