Version 1.0

The code work with GS1 Datamatrix barcodes used on the medicine packs as per EU FMD guidelines. This version does not support the PPN barcodes.

expiry_date_validation.py

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+from datetime import datetime
+
+
+def expiry_date_check(e:str):
+    my_year = e[:2]
+    my_month = e[2:4]
+    my_date = e[4:]
+    if (int(my_month) not in range(1,13)):
+        return False
+    elif (int(my_date) not in range(32)):
+        return False
+    
+    if my_date == '00':
+        if my_month == '02' and int(my_year) % 4 == 0:
+            my_date = '29'
+        elif my_month == '02' and int(my_year) % 4 != 0:
+            my_date = '28'
+        elif my_month in ['01', '03', '05', '07', '08', '10', '12']:
+            my_date = '31'
+        else:
+            my_date = '30'
+
+    actual_date = my_year + my_month + my_date
+    if actual_date > datetime.today().strftime('%y%m%d'):
+        return True
+    else:
+        return False
+    

gs1_gtin_validation.py

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+"""
+The function perform validation on the GS1-GTIN(14)
+
+"""
+
+def gtin_check(g: str):
+    digit_sum = (int(g[0]) * 3) + int(g[1]) + (int(g[2]) * 3) + int(g[3]) + (int(g[4]) * 3) + int(g[5]) + (int(g[6]) * 3) + int(g[7]) + (int(g[8]) * 3) + int(g[9]) + (int(g[10]) * 3) + int(g[11]) + (int(g[12]) * 3)
+    nearest_ten = round(digit_sum/10) * 10
+    check_sum_digit = nearest_ten - digit_sum
+    return check_sum_digit == int(g[-1])
+

pharma_datamatrix.py

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+"""
+The function parse the GS1 Datamatrix barcode used for medicine packs.
+The barcodes output is in below format:
+]d201034531200000111719112510ABCD1234<GS>2110EW354EWER
+(01)03453120000011(17)191125(10)ABCD1234<GS>(21)10EW354EWER
+(01) = GTIN Identifier - Fixed 14 chars
+(17) = Expiry Date Identifer - Fixed 6 Chars
+(10) = Batch Identifier - Variable length. (upto 20 chars usually between 4 - 10 Chars)
+(21) = Serial Number - Variable length. (upto 20 chars - Usually between 12 - 20 Chars)
+The symbology identifier ]d2 and for the second FNC1, when used as a separator character is <GS> Group-Separator.
+
+"""
+from gs1_gtin_validation import gtin_check
+from expiry_date_validation import expiry_date_check
+
+def pharma_datamatrix(barcode: str, validation: bool = False):
+    result = dict()
+    result['NHRN'] = None
+    if barcode[:3] == ']d2':
+        barcode = barcode[3:] 
+    while barcode:
+
+        if barcode[:2] == '01':
+            result['GTIN'] = barcode[2:16]
+            barcode = barcode[16:]
+
+        elif barcode[:2] == '17':
+            result['EXPIRY'] = barcode[2:8]
+            barcode = barcode[8:]
+
+        elif barcode[:2] == '10':
+            if chr(29) in barcode:
+                for i, c in enumerate(barcode):
+                    if ord(c) == 29:
+                        result['BATCH'] = barcode[2:i]
+                        barcode = barcode[i+1:]
+                        break
+            else:
+                result['BATCH'] = barcode[2:]
+                barcode = None
+                
+        elif barcode[:2] == '21':
+            if chr(29) in barcode:
+                #print("In the serial GS check")
+                for i, c in enumerate(barcode):
+                    if ord(c) == 29:
+                        result['SERIAL'] = barcode[2:i]
+                        barcode = barcode[i+1:]
+                        break
+            else:
+                result['SERIAL'] = barcode[2:]
+                barcode = None
+
+
+        elif barcode[:3] in ['710', '711', '712', '713', '714']:
+            if chr(29) in barcode:
+                for i, c in enumerate(barcode):
+                    if ord(c) == 29:
+                        result['NHRN'] = barcode[2:i]
+                        barcode = barcode[i+1:]
+                        break
+            else:
+                result['NHRN'] = barcode[2:]
+                barcode = None
+
+        else:
+            return f"Not a valid barcode"
+
+    if validation:
+        if gtin_check(result['GTIN']) == False and expiry_date_check(result['EXPIRY']) == False:
+            return f'INVALID GTIN & EXPIRY DATE'
+        elif expiry_date_check(result['EXPIRY']) == False:
+            return f'INVALID EXPIRY DATE'
+        elif gtin_check(result['GTIN']) == False:
+            return f'INVALID GTIN'
+        else:
+            return result
+    else:
+        return result
+
+            
+
+
+
+
+
+result = pharma_datamatrix("01083860077038511724013110HN5R21587E4RT10P")
+
+print(result)
+
+