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[Bug]: Python APIRequestContext silently drops float and bool values supplied through dictionary-based multipart data #43185
Description
Version
1.62.1.dev18+g6b0021ec7
Steps to reproduce
Run:
from playwright.sync_api import sync_playwright
with sync_playwright() as p:
request = p.request.new_context()
for value in [42.5, True, "hello"]:
response = request.post(
"https://httpbin.org/post",
multipart={"value": value},
)
print(repr(value), "->", response.json()["form"])
request.dispose()Expected behavior
float and bool values accepted by the Python multipart type should be serialized as multipart form fields rather than silently dropped.
For example:
42.5 -> {'value': '42.5'}
True -> {'value': 'true'}
Actual behavior
(env) ss@ss-Predator-PH315-53:~/playwright-python$ python abc.py
42.5 -> {}
True -> {}
'hello' -> {'value': 'hello'}
(env) ss@ss-Predator-PH315-53:~/playwright-python$
### Additional context
The Python implementation currently handles dictionary-based `multipart` values as follows:
```python
for name, value in multipart.items():
if is_file_payload(value):
...
elif isinstance(value, str):
multipart_data.append(FormField(name=name, value=value))
There is no corresponding handling for float or bool, so those values fall through without generating a FormField.
The Python MultipartType explicitly includes these types:
MultipartType = Union[
Dict[str, Union[bytes, bool, float, str, FilePayload]],
FormData
]The bundled JavaScript implementation handles the corresponding values and converts strings, numbers, and booleans to strings before creating the form field.
As an end-to-end comparison using the bundled Playwright Node runtime:
42.5 -> { value: '42.5' }
true -> { value: 'true' }
"hello" -> { value: 'hello' }
So the Python and JavaScript APIs currently behave differently for float and bool values supplied through dictionary-based multipart data.
Environment
System:
OS: Linux 6.8 Ubuntu 22.04.5 LTS 22.04.5 LTS (Jammy Jellyfish)
CPU: (16) x64 Intel(R) Core(TM) i7-10870H CPU @ 2.20GHz
Memory: 4.79 GB / 15.45 GB
Container: Yes
Binaries:
Node: 18.20.4 - /home/ss/.nvm/versions/node/v18.20.4/bin/node
Yarn: 1.22.22 - /home/ss/.nvm/versions/node/v18.20.4/bin/yarn
npm: 10.7.0 - /home/ss/.nvm/versions/node/v18.20.4/bin/npm
IDEs:
VSCode: 1.140.0 - /snap/bin/code
Languages:
Bash: 5.1.16 - /usr/bin/bash
Activity
suraj-self commentedon Oct 7, 2026
If this issue is confirmed as a bug and is suitable for a community contribution, I’d be happy to work on the fix.
alok-108 commentedon Oct 7, 2026
Confirmed — this is indeed a bug in
playwright-python.In
playwright/_impl/_fetch.py(lines 426–438), whenmultipartis provided as a dictionary, onlyisinstance(value, str)andis_file_payload(value)were handled, causingint,float, andboolvalues to fall through and get silently dropped. In contrast, whenmultipartis aFormDatainstance,_form_data_field_to_form_fieldhandles(str, int, float, bool).I've submitted a fix with regression tests on
microsoft/playwright-pythonin PR microsoft/playwright-python#3226.suraj-self commentedon Oct 7, 2026
I have already reproduced and analysed the root cause, implemented and locally verified a minimal fix, including regression tests.
Following Playwright’s contribution guidelines, I held off on opening a PR until the issue could be triaged/approved.
I would like to work on the fix if the issue is approved for community contribution.
pavelfeldman commentedon Oct 7, 2026
Go ahead with the Python fix
suraj-self commentedon Oct 7, 2026
Thank you, Pavel Feldman (@pavelfeldman) ! Really appreciate the go-ahead. I’ve opened the PR with the fix and regression tests. Please feel free to share any feedback when you have a chance. 🙏