Fix for Ambiguous Boolean Evaluation Error in PaddleOCR with Python 3.11

[agfianf]

This commit resolves the issue where dt_boxes was evaluated as a boolean in Python 3.11, leading to a ValueError. The condition if not dt_boxes: is replaced with if dt_boxes.size == 0: to explicitly check for an empty array, ensuring compatibility with Python 3.11 and maintaining the intended functionality.

PR 类型 PR types

Bug Fixes

PR 变化内容类型 PR changes

Others

描述 Description

Issue:

When using PaddleOCR in a Python 3.11 environment, an error is encountered during text detection only mode (det=True, rec=False). The error arises from the evaluation of dt_boxes as a boolean condition in an if not dt_boxes: statement. This behavior leads to a ValueError due to the ambiguous boolean evaluation of a NumPy array with more than one element.

Python Version Affected:

Python 3.11

Error Message:

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

Proposed Solution:

The issue can be resolved by modifying the conditional check for dt_boxes. Instead of using if not dt_boxes:, it is recommended to check if the array is empty by evaluating its size.

Suggested Change:

In the file where the error occurs, replace the following line:

if not dt_boxes:
    ocr_res.append(None)
    continue

with:

if dt_boxes.size == 0:
    ocr_res.append(None)
    continue

Rationale:

Using dt_boxes.size == 0 provides a clear and unambiguous method to check if dt_boxes is empty. This change ensures compatibility across different Python versions, particularly with the stricter boolean evaluation in Python 3.11.

Impact:

This change will prevent the ValueError and ensure that the text detection functionality of PaddleOCR works as intended in Python 3.11 environments.

提PR之前的检查 Check-list

• 这个 PR 是提交到dygraph分支或者是一个cherry-pick，否则请先提交到dygarph分支。
  This PR is pushed to the dygraph branch or cherry-picked from the dygraph branch. Otherwise, please push your changes to the dygraph branch.
• 这个PR清楚描述了功能，帮助评审能提升效率。This PR have fully described what it does such that reviewers can speedup.
• 这个PR已经经过本地测试。This PR can be convered by current tests or already test locally by you.

[CLAassistant]

All committers have signed the CLA.

[shiyutang]

LGTM