如何按列主要顺序显示数字序列?

时间:2017-09-20 00:30:23

标签: python loops for-loop nested-lists

计划说明: 找到1到4,027之间的所有素数,然后将它们打印在一个表格中 "读取",使用尽可能少的行,并使用尽可能少的纸张 尽可能。 (这是因为我必须在纸上将它们打印出来才能将其打开。)所有数字在其专栏中应该是右对齐的。高度 列可能都是相同的,除了最后一列, 它的底行可能有一些空白条目。

我的第一个功能的计划是找到上述范围之间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一个向上读取的表中显示列表。

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...

这一切我都能够自己想出来:

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。我记得在上一课中使用Java,我相信我们必须在for循环中使用for循环。我是否必须做类似的事情?

1 个答案:

答案 0 :(得分:1)

虽然我经常不回答原始海报甚至没有尝试自己解决问题的问题,但我决定将你的问题作为例外 - 主要是因为我发现它是一个有趣(并且具有惊人挑战性)的问题这需要解决一些棘手的子问题。

我还通过利用一些知名的计算快捷键来计算它们,从而略微优化了find_primes()函数。

出于测试和演示的目的,我只将表格设置为15行,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