Change occurrences of str.format to f-strings (#4118)

* f-string update rsa_cipher.py

* f-string update rsa_key_generator.py

* f-string update burrows_wheeler.py

* f-string update non_recursive_segment_tree.py

* f-string update red_black_tree.py

* f-string update deque_doubly.py

* f-string update climbing_stairs.py

* f-string update iterating_through_submasks.py

* f-string update knn_sklearn.py

* f-string update 3n_plus_1.py

* f-string update quadratic_equations_complex_numbers.py

* f-string update nth_fibonacci_using_matrix_exponentiation.py

* f-string update sherman_morrison.py

* f-string update levenshtein_distance.py

* fix lines that were too long

ciphers/rsa_cipher.py

@@ -118,7 +118,7 @@ def encryptAndWriteToFile(
     for i in range(len(encryptedBlocks)):
         encryptedBlocks[i] = str(encryptedBlocks[i])
     encryptedContent = ",".join(encryptedBlocks)
-    encryptedContent = "{}_{}_{}".format(len(message), blockSize, encryptedContent)
+    encryptedContent = f"{len(message)}_{blockSize}_{encryptedContent}"
     with open(messageFilename, "w") as fo:
         fo.write(encryptedContent)
     return encryptedContent

ciphers/rsa_key_generator.py

@@ -49,11 +49,11 @@ def makeKeyFiles(name: int, keySize: int) -> None:
     publicKey, privateKey = generateKey(keySize)
     print("\nWriting public key to file %s_pubkey.txt..." % name)
     with open("%s_pubkey.txt" % name, "w") as out_file:
-        out_file.write("{},{},{}".format(keySize, publicKey[0], publicKey[1]))
+        out_file.write(f"{keySize},{publicKey[0]},{publicKey[1]}")
 
     print("Writing private key to file %s_privkey.txt..." % name)
     with open("%s_privkey.txt" % name, "w") as out_file:
-        out_file.write("{},{},{}".format(keySize, privateKey[0], privateKey[1]))
+        out_file.write(f"{keySize},{privateKey[0]},{privateKey[1]}")
 
 
 if __name__ == "__main__":

compression/burrows_wheeler.py

@@ -157,11 +157,12 @@ if __name__ == "__main__":
     entry_msg = "Provide a string that I will generate its BWT transform: "
     s = input(entry_msg).strip()
     result = bwt_transform(s)
-    bwt_output_msg = "Burrows Wheeler transform for string '{}' results in '{}'"
+    print(
-    print(bwt_output_msg.format(s, result["bwt_string"]))
+        f"Burrows Wheeler transform for string '{s}' results "
-    original_string = reverse_bwt(result["bwt_string"], result["idx_original_string"])
+        f"in '{result['bwt_string']}'"
-    fmt = (
+    )
-        "Reversing Burrows Wheeler transform for entry '{}' we get original"
+    original_string = reverse_bwt(result["bwt_string"], result["idx_original_string"])
-        " string '{}'"
+    print(
+        f"Reversing Burrows Wheeler transform for entry '{result['bwt_string']}' "
+        f"we get original string '{original_string}'"
     )
-    print(fmt.format(result["bwt_string"], original_string))

data_structures/binary_tree/non_recursive_segment_tree.py

@@ -49,7 +49,7 @@ class SegmentTree:
         :param arr: list of elements for the segment tree
         :param fnc: commutative function for combine two elements
 
-        >>> SegmentTree(['a', 'b', 'c'], lambda a, b: '{}{}'.format(a, b)).query(0, 2)
+        >>> SegmentTree(['a', 'b', 'c'], lambda a, b: f'{a}{b}').query(0, 2)
         'abc'
         >>> SegmentTree([(1, 2), (2, 3), (3, 4)],
         ...             lambda a, b: (a[0] + b[0], a[1] + b[1])).query(0, 2)

data_structures/binary_tree/red_black_tree.py

@@ -475,11 +475,13 @@ class RedBlackTree:
         from pprint import pformat
 
         if self.left is None and self.right is None:
-            return "'{} {}'".format(self.label, (self.color and "red") or "blk")
+            return f"'{self.label} {(self.color and 'red') or 'blk'}'"
         return pformat(
             {
-                "%s %s"
+                f"{self.label} {(self.color and 'red') or 'blk'}": (
-                % (self.label, (self.color and "red") or "blk"): (self.left, self.right)
+                    self.left,
+                    self.right,
+                )
             },
             indent=1,
         )

data_structures/linked_list/deque_doubly.py

@@ -20,8 +20,8 @@ class _DoublyLinkedBase:
             self._next = link_n
 
         def has_next_and_prev(self):
-            return " Prev -> {}, Next -> {}".format(
+            return (
-                self._prev is not None, self._next is not None
+                f" Prev -> {self._prev is not None}, Next -> {self._next is not None}"
             )
 
     def __init__(self):

dynamic_programming/climbing_stairs.py

@@ -25,8 +25,9 @@ def climb_stairs(n: int) -> int:
         ...
     AssertionError: n needs to be positive integer, your input -7
     """
-    fmt = "n needs to be positive integer, your input {}"
+    assert (
-    assert isinstance(n, int) and n > 0, fmt.format(n)
+        isinstance(n, int) and n > 0
+    ), f"n needs to be positive integer, your input {n}"
     if n == 1:
         return 1
     dp = [0] * (n + 1)

dynamic_programming/iterating_through_submasks.py

@@ -37,8 +37,9 @@ def list_of_submasks(mask: int) -> list[int]:
 
     """
 
-    fmt = "mask needs to be positive integer, your input {}"
+    assert (
-    assert isinstance(mask, int) and mask > 0, fmt.format(mask)
+        isinstance(mask, int) and mask > 0
+    ), f"mask needs to be positive integer, your input {mask}"
 
     """
     first submask iterated will be mask itself then operation will be performed

machine_learning/knn_sklearn.py

@@ -26,6 +26,6 @@ X_new = [[1, 2, 1, 4], [2, 3, 4, 5]]
 prediction = knn.predict(X_new)
 
 print(
-    "\nNew array: \n {}"
+    f"\nNew array: \n {X_new}\n\nTarget Names Prediction: \n"
-    "\n\nTarget Names Prediction: \n {}".format(X_new, iris["target_names"][prediction])
+    f" {iris['target_names'][prediction]}"
 )

maths/3n_plus_1.py

@@ -9,7 +9,7 @@ def n31(a: int) -> tuple[list[int], int]:
     """
 
     if not isinstance(a, int):
-        raise TypeError("Must be int, not {}".format(type(a).__name__))
+        raise TypeError(f"Must be int, not {type(a).__name__}")
     if a < 1:
         raise ValueError(f"Given integer must be greater than 1, not {a}")
 

maths/quadratic_equations_complex_numbers.py

@@ -30,8 +30,8 @@ def quadratic_roots(a: int, b: int, c: int) -> tuple[complex, complex]:
 
 
 def main():
-    solutions = quadratic_roots(a=5, b=6, c=1)
+    solution1, solution2 = quadratic_roots(a=5, b=6, c=1)
-    print("The solutions are: {} and {}".format(*solutions))
+    print(f"The solutions are: {solution1} and {solution2}")
 
 
 if __name__ == "__main__":

matrix/nth_fibonacci_using_matrix_exponentiation.py

@@ -71,13 +71,13 @@ def nth_fibonacci_bruteforce(n):
 
 
 def main():
-    fmt = (
-        "{} fibonacci number using matrix exponentiation is {} and using bruteforce "
-        "is {}\n"
-    )
     for ordinal in "0th 1st 2nd 3rd 10th 100th 1000th".split():
         n = int("".join(c for c in ordinal if c in "0123456789"))  # 1000th --> 1000
-        print(fmt.format(ordinal, nth_fibonacci_matrix(n), nth_fibonacci_bruteforce(n)))
+        print(
+            f"{ordinal} fibonacci number using matrix exponentiation is "
+            f"{nth_fibonacci_matrix(n)} and using bruteforce is "
+            f"{nth_fibonacci_bruteforce(n)}\n"
+        )
     # from timeit import timeit
     # print(timeit("nth_fibonacci_matrix(1000000)",
     #              "from main import nth_fibonacci_matrix", number=5))

matrix/sherman_morrison.py

@@ -175,9 +175,7 @@ class Matrix:
                         result[r, c] += self[r, i] * another[i, c]
             return result
         else:
-            raise TypeError(
+            raise TypeError(f"Unsupported type given for another ({type(another)})")
-                "Unsupported type given for another ({})".format(type(another))
-            )
 
     def transpose(self):
         """
@@ -260,7 +258,7 @@ if __name__ == "__main__":
         print(f"v is {v}")
         print("uv^T is %s" % (u * v.transpose()))
         # Sherman Morrison
-        print("(a + uv^T)^(-1) is {}".format(ainv.ShermanMorrison(u, v)))
+        print(f"(a + uv^T)^(-1) is {ainv.ShermanMorrison(u, v)}")
 
     def test2():
         import doctest

strings/levenshtein_distance.py

@@ -69,8 +69,4 @@ if __name__ == "__main__":
     second_word = input("Enter the second word:\n").strip()
 
     result = levenshtein_distance(first_word, second_word)
-    print(
+    print(f"Levenshtein distance between {first_word} and {second_word} is {result}")
-        "Levenshtein distance between {} and {} is {}".format(
-            first_word, second_word, result
-        )
-    )