Python计算一个表的所有可能组合

Question

我有一个如下所示的表格:

   PotA  PotB  PotC  PotD  PotE
A   +     +     +     +     +
B   -     ?     +     +     ?
C   +     +     +     +     +
D   +     -     +     -     +
E   +     +     +     +     +

从这里，我必须找到“+”、“-”和“?”的所有可能组合。对于(PotA 和 PotB)、(PotA 和 PotC)的所有组合，等等，(PotA、PotB 和 PotC)，最后到(PotA、PotB、PotC、PotD 和 PotE)。实际上，“Pot”行一直在继续，但为了简化，这里我只显示直到 PotE。

为此，首先，我按如下方式读取文件，然后生成两个组合的所有可能可能性，以计算每种可能性。

def readDatafile():
    filename = ("data.txt")
    infile = open(filename,'r')

    for line in infile.readlines():
        line = line.strip()
        print (line)          # just to check the data, need to carry on from here.

"""Generate all possible permutations for later count"""
def doPermutations(items, n):
    if n == 0:
        yield ''
    else:
        for i in range(len(items)):
            for base in doPermutations(items, n - 1):
                yield str(items[i]) + str(base)

def makeAllPossibleList():
    nlength      = 2          # This should go outside of the function and will be same as the number of Pots
    lpossibility = ['+', '-', '?']
    litems       = []

    for i in doPermutations(lpossibility, int(nlength)):
        litems.append(i)

    for x in items:
        print (x)             # This generate all the possible items for combination of two

所以，最终的结果是这样的:

Combination: Possibility Count
PotA, PotB: ++ 3
PotA, PotB: +- 1
PotA, PotB: +? 0
PotA, PotB: -+ 0
PotA, PotB: -- 0
PotA, PotB: -? 1
PotA, PotB: ?+ 0
PotA, PotB: ?- 0
PotA, PotB: ?? 0
PotA, PotC: ...
PotA, PotC: ...
.......
PotA, PotB, PotC, PotD, PotE: +++++ 3
PotA, PotB, PotC, PotD, PotE: ++++- 0
PotA, PotB, PotC, PotD, PotE: ++++? 0
.......

是否有任何好的 python 方法来获取此问题的正确逻辑？我是否必须以标题作为键并以列作为列表的值来读取数据？

我无法得到正确的逻辑。请给我一些帮助。

Answer 1

假设我明白你在追求什么，那么像这样的东西怎么样:

import itertools
import collections

def read_table(filename):
    with open(filename) as fp:
        header = next(fp).split()
        rows = [line.split()[1:] for line in fp if line.strip()]
        columns = zip(*rows)
    data = dict(zip(header, columns))
    return data

table = read_table("data.txt")
pots = sorted(table)

alphabet = "+-?"
for num in range(2, len(table)+1):
    for group in itertools.combinations(pots, num):
        patterns = zip(*[table[p] for p in group])
        counts = collections.Counter(patterns)
        for poss in itertools.product(alphabet, repeat=num):
            print ', '.join(group) + ':',
            print ''.join(poss), counts[poss]

---

产生:

PotA, PotB: ++ 3
PotA, PotB: +- 1
PotA, PotB: +? 0
PotA, PotB: -+ 0
PotA, PotB: -- 0
PotA, PotB: -? 1
PotA, PotB: ?+ 0
PotA, PotB: ?- 0
PotA, PotB: ?? 0
PotA, PotC: ++ 4
[...]
PotA, PotB, PotC, PotD, PotE: +++++ 3
PotA, PotB, PotC, PotD, PotE: ++++- 0
[...]

请注意，我假设您想要的输出是错误的，因为在这一行中:

PotA, PotB, PotC, PotD, PotE: ++++++ 2

左边有五列，右边有六个 + 符号。