import random


def format_len(value, size: int = 6, placeholder: str = " ", loc: str = "right"):
    """
    控制字符长度, 如果不够长, 默认在左侧添加空格占位符. 如果比size长, 则截断
    :param value: 值
    :param size: 控制的长度
    :param placeholder: 占位符
    :param loc: 占位符添加位置, left or right
    :return: str
    """
    value = str(value)
    v_len = len(value)

    if v_len > size:
        value = value[:size]
    elif v_len < size:
        place_char = ""
        for p in range(size - v_len):
            place_char += placeholder
        if loc == "right":
            value = value + place_char
        else:
            value = place_char + value

    return value


with open('test_print.txt', 'w') as fw:
    for i in range(10):
        for j in range(10):
            v = random.randint(0, 10000)
            print(v)
            v = format_len(v, 8)
            print(v)

            fw.write("{}\t".format(v))
        fw.write('\n')

输入结果：