Retrieve recognised text from JSON returned by Microsoft OCR

Question

The Microsoft OCR API returns json, and if I want to extact the text data from this json:

response = \
{
 "language": "en",
 "textAngle": -2.0000000000000338,
 "orientation": "Up",
 "regions": [
 {
 "boundingBox": "462,379,497,258",
 "lines": [
 {
 "boundingBox": "462,379,497,74",
 "words": [
 {
 "boundingBox": "462,379,41,73",
 "text": "A"
 },
 {
 "boundingBox": "523,379,153,73",
 "text": "GOAL"
 },
 {
 "boundingBox": "694,379,265,74",
 "text": "WITHOUT"
 }
 ]
 },
 {
 "boundingBox": "565,471,289,74",
 "words": [
 {
 "boundingBox": "565,471,41,73",
 "text": "A"
 },
 {
 "boundingBox": "626,471,150,73",
 "text": "PLAN"
 },
 {
 "boundingBox": "801,472,53,73",
 "text": "IS"
 }
 ]
 },
 {
 "boundingBox": "519,563,375,74",
 "words": [
 {
 "boundingBox": "519,563,149,74",
 "text": "JUST"
 },
 {
 "boundingBox": "683,564,41,72",
 "text": "A"
 },
 {
 "boundingBox": "741,564,153,73",
 "text": "WISH"
 }
 ]
 }
 ]
 }
 ]
}

def check_for_word(ocr):
 # Initialise our subject to None
 print("OCR: {}".format(ocr))
 subject = None
 for region in ocr["regions"]:
 if "lines" in region:
 for lines in region["lines"]:
 if "words" in lines:
 for word in lines["words"]:
 if "text" in word:
 subject = word["text"].lower()
 break
 print("OCR word is {}".format(subject))
 return subject
print(response["regions"][0]["lines"][0]["words"][0]["text"]) # Should return this
print(check_for_word(response))

• Each dictionary has arrays and we are unsure if the array contains any element
• Also not sure if the dictionary has key

Let's say we just wish to return the first text it matched from the image file.

This code works but it has a deep nested structure that has bad smell. Is there a better practice to write this in a cleaner way?

Answer 1

One way to almost halve the number of lines (and levels of indentation) needed is to use dict.get with [] as the optional default option:

def check_for_word(ocr):
 for region in ocr["regions"]:
 for lines in region.get("lines", []):
 for word in lines.get("words", []):
 if "text" in word:
 return word["text"].lower()
 else:
 raise KeyError("OCR word not found")

I would also move the printing outside the function, so you can immediately return and add a else clause to catch the case that it is not present (this part could also be done outside with your code by checking for None).