Merge pull request #65 from ikostan/exercism-sync/ff0dd5a6a0fa92c6

[Sync Iteration] python/pig-latin/5

Author: ikostan

solutions/python/pig-latin/5/pig_latin.py

@@ -0,0 +1,155 @@
+"""
+The task is to translate text from English to Pig Latin.
+The translation is defined using four rules, which look at the pattern of vowels
+and consonants at the beginning of a word. These rules look at each word's use
+of vowels and consonants:
+
+vowels: the letters a, e, i, o, and u
+consonants: the other 21 letters of the English alphabet
+"""
+
+
+def translate(text: str) -> str:
+    """
+    Translate text from English to Pig Latin.
+
+    :param text:
+    :return:
+    """
+    words: list = text.split(" ")
+    return " ".join(process_text(word) for word in words)
+
+
+def process_text(text: str) -> str:
+    """
+    Convert a string based on 4 rules of Pig Latin.
+
+    :param text:
+    :return:
+    """
+    # Rule 1
+    if is_rule_1(text):
+        # If a word begins with a vowel,
+        # or starts with "xr" or "yt",
+        # add an "ay" sound to the end of the word.
+        return text + "ay"
+
+    # Rule 2
+    if is_rule_2(text):
+        # If a word begins with one or more consonants, first move those consonants
+        # to the end of the word and then add an "ay" sound to the end of the word.
+        i = get_last_consonant_indx(text)
+        return text[i + 1 :] + text[: i + 1] + "ay"
+
+    # Rule 3
+    if is_rule_3(text):
+        # If a word starts with zero or more consonants followed by "qu", first move
+        # those consonants (if any) and the "qu" part to the end of the word, and then
+        # add an "ay" sound to the end of the word.
+        i = text.index("qu")
+        return text[i + 2 :] + text[: i + 2] + "ay"
+
+    # Rule 4
+    if is_rule_4(text):
+        # If a word starts with one or more consonants followed by "y", first move the
+        # consonants preceding the "y" to the end of the word, and then add an "ay" sound
+        # to the end of the word.
+        i = text.index("y")
+        return text[i:] + text[:i] + "ay"
+
+    raise ValueError(f"Unhandled word in Pig Latin translation: '{text}'")
+
+
+def is_rule_1(text: str) -> bool:
+    """
+    Check if a word begins with a vowel, or starts with "xr" or "yt".
+
+    :param text:
+    :return:
+    """
+    if is_vowel(text[0]):
+        return True
+    if text[:2] in ("xr", "yt"):
+        return True
+    return False
+
+
+def is_rule_2(text: str) -> bool:
+    """
+    Check ff a word begins with one or more consonants.
+    No 'qu' or 'y' in it.
+
+    :param text:
+    :return:
+    """
+    return is_consonant(text[0]) and not is_rule_3(text) and not is_rule_4(text)
+
+
+def is_rule_3(text: str) -> bool:
+    """
+    Check if a word starts with zero or more consonants followed by "qu".
+
+    :param text:
+    :return:
+    """
+    if "qu" in text:
+        if text[:2] == "qu":
+            return True
+
+        for char in text[: text.index("qu")]:
+            if is_vowel(char):
+                return False
+        return True
+    return False
+
+
+def is_rule_4(text: str) -> bool:
+    """
+    Check if a word starts with one or more consonants followed by "y".
+
+    :param text:
+    :return:
+    """
+    if "y" in text and text[0] != "y":
+        for char in text[: text.index("y")]:
+            if is_vowel(char):
+                return False
+        return True
+    return False
+
+
+def is_vowel(char: str) -> bool:
+    """
+    Test that char in vowels: the letters a, e, i, o, and u.
+
+    :param char:
+    :return:
+    """
+    return char in "aeiou"
+
+
+def is_consonant(char: str) -> bool:
+    """
+    Check that char is consonant (the other 21 letters of the English alphabet).
+
+    :param char:
+    :return:
+    """
+    return char.isalpha() and not is_vowel(char)
+
+
+def get_last_consonant_indx(text: str) -> int:
+    """
+    Get last index of consonant inside the string.
+
+    :param text:
+    :return:
+    """
+    i = 0
+    for n, char in enumerate(text):
+        if is_consonant(char):
+            i = n
+        else:
+            break
+
+    return i