Simplify

day03-1.py

 debug = helper.debug
 load_input = helper.load_input
 
-def is_digit(n):
-    try:
-        m = int(n)
-    except ValueError:
-        return False
-    return True
 
 class InputNumber:
     def __init__(self, number, start_pos, end_pos, line):
         self.line = line
 
     def _is_symbol(self, char):
-        return (char != "." and not is_digit(char))
+        return (char != "." and not char.isdigit())
 
     def _check_up(self, input):
         if self.line == 0:
     for j, line in enumerate(lines):
         i = 0
         while i < max_len:
-            if is_digit(line[i]):
+            if line[i].isdigit():
                 current_number = ""
                 start_pos = i
-                while i < max_len and is_digit(line[i]):
+                while i < max_len and line[i].isdigit():
                     current_number += f"{line[i]}"
                     i += 1
                 end_pos = i