如何以列优先顺序显示一系列数字？

Question

节目说明： 找出 1 到 4,027 之间的所有质数并将它们打印在一个表格中 “向下阅读”，使用尽可能少的行，并使用尽可能少的纸张 尽可能。 （这是因为我必须将它们打印在纸上才能上交。）所有数字在它们的列中都应该是右对齐的。高度 的列应该都是相同的，除了最后一列， 它的底行可能有一些空白条目。

我的第一个函数的计划是找到上述范围内的所有素数并将它们放在一个列表中。然后我希望我的第二个函数在从上到下的表格中显示列表。

2    23    59
3    29    61
5    31    67
7    37    71
11   41    73
13   43    79
17   47    83
19   53    89

等等……

这都是我自己想出来的：

def findPrimes(n):
    """ Adds calculated prime numbers to a list. """
    prime_list = list()
    for number in range(1, n + 1):
        prime = True
        for i in range(2, number):
            if(number % i == 0):
                prime = False
        if prime:
            prime_list.append(number)

    return prime_list

def displayPrimes():
    pass

print(findPrimes(4027))

我不确定如何在 Python 中显示行/列。我记得在我之前的课程中使用过 Java，我相信我们必须在 for 循环中使用 for 循环。我必须做类似的事情吗？

Answer 1

虽然我经常不回答原始发帖人甚至没有尝试自己解决问题的问题，但我决定将你的问题排除在外 - 主要是因为我发现这是一个有趣（而且具有惊人挑战性）的问题这需要解决一些有些棘手的子问题。

我还利用一些相对知名的计算快捷方式来稍微优化您的 find_primes() 函数。

出于测试和演示目的，我将表格设置为只有 15 行高，以强制生成多个页面，如最后的输出所示。

from itertools import zip_longest
import locale
import math
locale.setlocale(locale.LC_ALL, '')  # enable locale-specific formatting

def zip_discard(*iterables, _NULL=object()):
    """ Like zip_longest() but doesn't fill out all rows to equal length.
     https://stackoverflow.com/questions/38054593/zip-longest-without-fillvalue
    """
    return [[entry for entry in iterable if entry is not _NULL]
                for iterable in zip_longest(*iterables, fillvalue=_NULL)]

def grouper(n, seq):
    """ Group elements in sequence into groups of "n" items. """
    for i in range(0, len(seq), n):
        yield seq[i:i+n]

def tabularize(width, height, numbers):
    """ Print list of numbers in column-major tabular form given the dimensions
        of the table in characters (rows and columns). Will create multiple
        tables of required to display all numbers.
    """
    # Determine number of chars needed to hold longest formatted numeric value
    gap = 2  # including space between numbers
    col_width = len('{:n}'.format(max(numbers))) + gap

    # Determine number of columns that will fit within the table's width.
    num_cols = width // col_width
    chunk_size = num_cols * height  # maximum numbers in each table

    for i, chunk in enumerate(grouper(chunk_size, numbers), start=1):
        print('---- Page {} ----'.format(i))
        num_rows = int(math.ceil(len(chunk) / num_cols))  # rounded up
        table = zip_discard(*grouper(num_rows, chunk))
        for row in table:
            print(''.join(('{:{width}n}'.format(num, width=col_width)
                                                    for num in row)))

def find_primes(n):
    """ Create list of prime numbers from 1 to n. """
    prime_list = []
    for number in range(1, n+1):
        for i in range(2, int(math.sqrt(number)) + 1):
            if not number % i:  # Evenly divisible?
                break  # Not prime.
        else:
            prime_list.append(number)

    return prime_list

primes = find_primes(4027)
tabularize(80, 15, primes)

输出：

---- Page 1 ----
      1     47    113    197    281    379    463    571    659    761    863
      2     53    127    199    283    383    467    577    661    769    877
      3     59    131    211    293    389    479    587    673    773    881
      5     61    137    223    307    397    487    593    677    787    883
      7     67    139    227    311    401    491    599    683    797    887
     11     71    149    229    313    409    499    601    691    809    907
     13     73    151    233    317    419    503    607    701    811    911
     17     79    157    239    331    421    509    613    709    821    919
     19     83    163    241    337    431    521    617    719    823    929
     23     89    167    251    347    433    523    619    727    827    937
     29     97    173    257    349    439    541    631    733    829    941
     31    101    179    263    353    443    547    641    739    839    947
     37    103    181    269    359    449    557    643    743    853    953
     41    107    191    271    367    457    563    647    751    857    967
     43    109    193    277    373    461    569    653    757    859    971
---- Page 2 ----
    977  1,069  1,187  1,291  1,427  1,511  1,613  1,733  1,867  1,987  2,087
    983  1,087  1,193  1,297  1,429  1,523  1,619  1,741  1,871  1,993  2,089
    991  1,091  1,201  1,301  1,433  1,531  1,621  1,747  1,873  1,997  2,099
    997  1,093  1,213  1,303  1,439  1,543  1,627  1,753  1,877  1,999  2,111
  1,009  1,097  1,217  1,307  1,447  1,549  1,637  1,759  1,879  2,003  2,113
  1,013  1,103  1,223  1,319  1,451  1,553  1,657  1,777  1,889  2,011  2,129
  1,019  1,109  1,229  1,321  1,453  1,559  1,663  1,783  1,901  2,017  2,131
  1,021  1,117  1,231  1,327  1,459  1,567  1,667  1,787  1,907  2,027  2,137
  1,031  1,123  1,237  1,361  1,471  1,571  1,669  1,789  1,913  2,029  2,141
  1,033  1,129  1,249  1,367  1,481  1,579  1,693  1,801  1,931  2,039  2,143
  1,039  1,151  1,259  1,373  1,483  1,583  1,697  1,811  1,933  2,053  2,153
  1,049  1,153  1,277  1,381  1,487  1,597  1,699  1,823  1,949  2,063  2,161
  1,051  1,163  1,279  1,399  1,489  1,601  1,709  1,831  1,951  2,069  2,179
  1,061  1,171  1,283  1,409  1,493  1,607  1,721  1,847  1,973  2,081  2,203
  1,063  1,181  1,289  1,423  1,499  1,609  1,723  1,861  1,979  2,083  2,207
---- Page 3 ----
  2,213  2,333  2,423  2,557  2,687  2,789  2,903  3,037  3,181  3,307  3,413
  2,221  2,339  2,437  2,579  2,689  2,791  2,909  3,041  3,187  3,313  3,433
  2,237  2,341  2,441  2,591  2,693  2,797  2,917  3,049  3,191  3,319  3,449
  2,239  2,347  2,447  2,593  2,699  2,801  2,927  3,061  3,203  3,323  3,457
  2,243  2,351  2,459  2,609  2,707  2,803  2,939  3,067  3,209  3,329  3,461
  2,251  2,357  2,467  2,617  2,711  2,819  2,953  3,079  3,217  3,331  3,463
  2,267  2,371  2,473  2,621  2,713  2,833  2,957  3,083  3,221  3,343  3,467
  2,269  2,377  2,477  2,633  2,719  2,837  2,963  3,089  3,229  3,347  3,469
  2,273  2,381  2,503  2,647  2,729  2,843  2,969  3,109  3,251  3,359  3,491
  2,281  2,383  2,521  2,657  2,731  2,851  2,971  3,119  3,253  3,361  3,499
  2,287  2,389  2,531  2,659  2,741  2,857  2,999  3,121  3,257  3,371  3,511
  2,293  2,393  2,539  2,663  2,749  2,861  3,001  3,137  3,259  3,373  3,517
  2,297  2,399  2,543  2,671  2,753  2,879  3,011  3,163  3,271  3,389  3,527
  2,309  2,411  2,549  2,677  2,767  2,887  3,019  3,167  3,299  3,391  3,529
  2,311  2,417  2,551  2,683  2,777  2,897  3,023  3,169  3,301  3,407  3,533
---- Page 4 ----
  3,539  3,581  3,623  3,673  3,719  3,769  3,823  3,877  3,919  3,967  4,019
  3,541  3,583  3,631  3,677  3,727  3,779  3,833  3,881  3,923  3,989  4,021
  3,547  3,593  3,637  3,691  3,733  3,793  3,847  3,889  3,929  4,001  4,027
  3,557  3,607  3,643  3,697  3,739  3,797  3,851  3,907  3,931  4,003
  3,559  3,613  3,659  3,701  3,761  3,803  3,853  3,911  3,943  4,007
  3,571  3,617  3,671  3,709  3,767  3,821  3,863  3,917  3,947  4,013