TheAlgorithms-Python

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"""
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Arithmetic mean
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Reference: https://en.wikipedia.org/wiki/Arithmetic_mean
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Arithmetic series
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Reference: https://en.wikipedia.org/wiki/Arithmetic_series
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(The URL above will redirect you to arithmetic progression)
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"""
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def is_arithmetic_series(series: list) -> bool:
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    """
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    checking whether the input series is arithmetic series or not
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    >>> is_arithmetic_series([2, 4, 6])
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    True
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    >>> is_arithmetic_series([3, 6, 12, 24])
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    False
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    >>> is_arithmetic_series([1, 2, 3])
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    True
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    >>> is_arithmetic_series(4)
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    Traceback (most recent call last):
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        ...
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    ValueError: Input series is not valid, valid series - [2, 4, 6]
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    >>> is_arithmetic_series([])
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    Traceback (most recent call last):
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        ...
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    ValueError: Input list must be a non empty list
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    """
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    if not isinstance(series, list):
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        raise ValueError("Input series is not valid, valid series - [2, 4, 6]")
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    if len(series) == 0:
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        raise ValueError("Input list must be a non empty list")
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    if len(series) == 1:
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        return True
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    common_diff = series[1] - series[0]
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    for index in range(len(series) - 1):
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        if series[index + 1] - series[index] != common_diff:
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            return False
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    return True
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def arithmetic_mean(series: list) -> float:
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    """
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    return the arithmetic mean of series
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    >>> arithmetic_mean([2, 4, 6])
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    4.0
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    >>> arithmetic_mean([3, 6, 9, 12])
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    7.5
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    >>> arithmetic_mean(4)
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    Traceback (most recent call last):
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        ...
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    ValueError: Input series is not valid, valid series - [2, 4, 6]
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    >>> arithmetic_mean([4, 8, 1])
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    4.333333333333333
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    >>> arithmetic_mean([1, 2, 3])
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    2.0
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    >>> arithmetic_mean([])
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    Traceback (most recent call last):
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        ...
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    ValueError: Input list must be a non empty list
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    """
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    if not isinstance(series, list):
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        raise ValueError("Input series is not valid, valid series - [2, 4, 6]")
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    if len(series) == 0:
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        raise ValueError("Input list must be a non empty list")
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    answer = 0
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    for val in series:
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        answer += val
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    return answer / len(series)
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if __name__ == "__main__":
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    import doctest
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    doctest.testmod()
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