python: 打印星星塔

# print star_tower func;
def star_tower(char="*", num=7):
    """
    Based on observations of the model, n = floors:

    ------------*                   # 12 - [2*n-2*i]=12 and 1 *  [2*i-1]=1
    ----------* * *                 # 10 - [2*n-2*i]=10 and 3 *  [2*i-1]=3
    --------* * * * *               # 8  - [2*n-2*i]= 8 and 5 *  [2*i-1]=5
    ------* * * * * * *             # 6  - [2*n-2*i]= 6 and 7 *  [2*i-1]=7
    ----* * * * * * * * *           # 4  - [2*n-2*i]= 4 and 9 *  [2*i-1]=9
    --* * * * * * * * * * *         # 2  - [2*n-2*i]= 2 and 11 * [2*i-1]=11
    * * * * * * * * * * * * *       # 0  - [2*n-2*i]= 0 and 13 * [2*i-1]=13

    1. To print a 7-story tower, loop '7' times to print '7' lines of data;
    2. Each row consists of 'Spaces' and '*';
    3. According to observation, find the relationship between the number of 'Spaces' and the number of' floors';
    4. According to observation , find the relationship between the number of 'Spaces' and the number of' *';

    :param char: Provides the characters that make up the tower
    :param num: Provides the floors that make up the tower
    :return: None
    """
    n = int(num)  # cast to int?;
    for i in range(1, n + 1):  # according to number of the floors to loop;
        for k in range(2 * n - 2 * i):  # loop to print 'Spaces', the number is:[2*n-2*i];
            print("", end=" ")  # print 'Spaces',no \n;

        for j in range(2 * i - 1):  # loop to print '*', the number is:[2*i-1];
            print(char, end=" ") 
        print()  # out \n;

if __name__ == '__main__':
    star_tower("Y", '12')
    star_tower()