tesseract-4.0.0a支持下面psm。如果要具有单个字符识别，请设置psm = 10。并且如果您的文本仅包含数字，则可以设置tessedit_char_whitelist=0123456789。

Page segmentation modes:
  0    Orientation and script detection (OSD) only.
  1    Automatic page segmentation with OSD.
  2    Automatic page segmentation, but no OSD, or OCR.
  3    Fully automatic page segmentation, but no OSD. (Default)
  4    Assume a single column of text of variable sizes.
  5    Assume a single uniform block of vertically aligned text.
  6    Assume a single uniform block of text.
  7    Treat the image as a single text line.
  8    Treat the image as a single word.
  9    Treat the image as a single word in a circle.
 10    Treat the image as a single character.
 11    Sparse text. Find as much text as possible in no particular order.
 12    Sparse text with OSD.
 13    Raw line. Treat the image as a single text line,
                        bypassing hacks that are Tesseract-specific.

这是image_to_string带有多个参数的示例用法。

target = pytesseract.image_to_string(image, lang='eng', boxes=False, \
        config='--psm 10 --oem 3 -c tessedit_char_whitelist=0123456789')

希望这可以帮助。