TheAlgorithms · sarcastic-verma · May 18, 2020 · May 18, 2020 · May 18, 2020
diff --git a/conversions/base_changer.py b/conversions/base_changer.py
@@ -0,0 +1,113 @@
+def base_changer(num: str, from_base: int, to_base: int) -> str:
+    # set decimal value for each hexadecimal digit and vice versa
+    hex_codes = {
+        "A": 10,
+        "B": 11,
+        "C": 12,
+        "D": 13,
+        "E": 14,
+        "F": 15,
+        "G": 16,
+        "H": 17,
+        10: "A",
+        11: "B",
+        12: "C",
+        13: "D",
+        14: "E",
+        15: "F",
+        16: "G",
+        17: "H",
+    }
+
+    # split the number with decimal into before and after decimal point if any.
+    splitter = num.split(".")
+    before_dec = 0
+    power = 0
+    num_int = splitter[0][::-1]
+    for i in num_int:
+        # to change to numbers only if base
+        # >10  for before decimal part
+        if i in hex_codes:
+            before_dec = before_dec + hex_codes[i] * (from_base ** power)
+        else:
+            i = int(i)
+            before_dec = before_dec + i * (from_base ** power)
+        power += 1
+
+    intermediate_result = before_dec
+
+    # to tackle after decimal part
+    if len(splitter) != 1:
+        point = 0
+        power = -1
+        num_before_dec = splitter[1]
+        for i in num_before_dec:
+            if i in hex_codes:
+                point = point + hex_codes[i] * (from_base ** power)
+            else:
+                i = int(i)
+                point = point + i * (from_base ** power)
+            power = power - 1
+        intermediate_result = intermediate_result + point
+    before_dec = []
+    after_dec = []
+
+    # as we already converted to base 10
+    if to_base == 10:
+        ans = intermediate_result
+        return ans
+    else:
+        intermediate_result = str(intermediate_result)
+        # to tackle decimals in intermediate_result if any
+        split_intermediate = intermediate_result.split(".")
+        intermediate_result = int(split_intermediate[0])
+        while intermediate_result >= to_base:
+            rem = intermediate_result % to_base
+            intermediate_result = intermediate_result // to_base
+            if rem in hex_codes:
+                before_dec.append(hex_codes[rem])
+            else:
+                before_dec.append(rem)
+        if intermediate_result in hex_codes:
+            before_dec.append(hex_codes[intermediate_result])
+        else:
+            before_dec.append(intermediate_result)
+        before_dec = before_dec[::-1]
+        ans = "".join([str(i) for i in before_dec])
+        # for part after decimal in intermediate_result
+
+        if len(splitter) != 1:
+            len_dec = len(split_intermediate[1])
+            intermediate_dec = int(split_intermediate[1])
+            for i in range(5):
+                multiply_intermediate_dec = str(intermediate_dec * to_base)
+                len_inter_dec = len(multiply_intermediate_dec)
+                if len_inter_dec > len_dec:
+                    appender = (
+                            multiply_intermediate_dec[: len_inter_dec - len_dec]
+                            + "."
+                            + multiply_intermediate_dec[len_inter_dec - len_dec:]
+                    )
+                else:
+                    appender = "0." + multiply_intermediate_dec
+                append_splitter = appender.split(".")
+                hex_check = int(append_splitter[0])
+                if hex_check in hex_codes:
+                    after_dec.append(hex_codes[hex_check])
+                else:
+                    after_dec.append(append_splitter[0])
+                intermediate_dec = int(append_splitter[1])
+            after_dec = "".join([str(i) for i in after_dec])
+            ans = ans + "." + after_dec
+        return ans
+
+
+if __name__ == "__main__":
+    num = input("Enter the number ").strip()
+    from_base = int(input("Enter the base(2-18) ").strip())
+    to_base = int(input("Enter the new base(2-18) ").strip())
+    if 18 >= from_base >= 2 and 18 >= to_base >= 2:
+        result = base_changer(num, from_base, to_base)
+        print(result)
+    else:
+        print("Invalid Inputs.")
diff --git a/conversions/decimal_to_binary.py b/conversions/decimal_to_binary.py
@@ -1,7 +1,7 @@
 """Convert a Decimal Number to a Binary Number."""
 
 
-def decimal_to_binary(num):
+def decimal_to_binary(num: int) -> str:
 
     """
         Convert a Integer Decimal Number to a Binary Number as str.