How to use 'if name main python' in Python

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def main():
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    """main"""
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    args = sys.argv[1:]
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    if len(args) != 1:
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        print('Usage: {} STR'.format(os.path.basename(sys.argv[0])))
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        sys.exit(1)
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    word = args[0]
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    lc_word = word.lower()
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    # Method 1:
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    # Create a variable to hold the count
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    # Use a `for` loop to go through each character in the word
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    # If that character is in the list of vowels, increment the counter
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    count = 0
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    for char in word.lower():
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        if char in 'aeiou':
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            count += 1
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    # Method 2:
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    # Create a variable to hold the count
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    # Use a `for` loop to go through the list of vowels
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    # Increment the count with the `str.count` function that will
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    # find how many times the vowel occurs in the word
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    # count = 0
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    # for vowel in "aeiou":
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    #     count += lc_word.count(vowel)
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    # Method 3:
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    # Use a list comprehension instead of a `for` loop to get a list 
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    # of integers which are the counts for each vowel
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    # Then use the `sum` function to add them together
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    # count = sum([lc_word.count(v) for v in "aeiou"])
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    # Method 4:
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    # Replace the list comprehension with a `map`
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    # count = sum(map(lc_word.count, "aeiou"))
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    print('There {} {} vowel{} in "{}."'.format(
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        'are' if count > 1 or count == 0 else 'is',
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        count,
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        '' if count == 1 else 's',
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        word))