Question

希望我在标题中已经解释得很好，但这就是我所拥有的：

输入数据：

Mushroom Kingdom, Mario

Hyrule, Link

Mushroom Kingdom, Bowser

Zebes, Samus

Zebes, Metroid

我想要运行这样的东西，

# The next three lines establish that I'll be reading proc as a file
import subprocess
cmd = 'external command that returns the above data'
proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)

homeworlds = {}

while True:
  line = proc.stdout.readline().split(',')
  if line:
    # If line isn't empty
    homeword = line[0]
    person = line[1]

    homeworlds[homeword] = list.append[person] # Good logic? Bad syntax?

  else:
   break

目标是我可以打电话：

print homeworlds['Mushroom Kingdom']

并返回列表

Mario, Bowser

Answer 1

在这里使用defaultdict会更容易。此外，您当前正在调用split()而没有任何参数。你真正想要做的是分开,。所以你应该致电split(',')。

所以你的代码应该看起来像这样：

homeworlds = collections.defaultdict(list)
while True:
  line = proc.stdout.readline().split(',')
  if line:
    # If line isn't empty
    homeworld = line[0].strip()
    person = line[1].strip()

    homeworlds[homeworld].append(person)

  else:
    break

Answer 2

 if not homeword in homeworlds:
    homeworlds[homeword] = list()
 homeworlds[homeword].append(person)

Answer 3

使用defaultdict

from collections import defaultdict
homeworlds = defaultdict(list)

homeworlds[homeword].append(person)

Answer 4

试试这个：

if homeword not in homeworlds:
    homeworlds[homeword] = []
homeworlds[homeword].append(person)

这会检查homeword中是否有homeworld的条目。如果没有，它会在那里添加一个列表。然后我们肯定知道我们在homeworld[homeword]有一个列表，因此我们可以在其上调用.append(person)。

Answer 5

以下是一致且优雅的解决方案（部分灵感来自其他答案）：

#!/bin/env python
from collections import defaultdict

lines = """Mushroom Kingdom, Mario

Hyrule, Link

Mushroom Kingdom, Bowser

Zebes, Samus

Zebes, Metroid
"""

homeworlds = defaultdict(list)

for line in lines.splitlines():
    if line and ',' in line:
        key, value = line.split(',')
        homeworlds[key].append(value.trim())

print(homeworlds)

Answer 6

Python 2.7.3rc2 (default, Apr 22 2012, 22:30:17) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> input_data = [('Mushroom Kingdom', 'Mario'),
...  ('Hyrule', 'Link'),
...  ('Mushroom Kingdom', 'Bowser'),
...  ('Zebes', 'Samus'),
...  ('Zebes', 'Metroid')]
>>> homeworlds = {}
>>> for homeword,person in input_data:
...   homeworlds.setdefault(homeword, []).append(person)
... 
>>> homeworlds
{'Hyrule': ['Link'], 'Zebes': ['Samus', 'Metroid'], 'Mushroom Kingdom': ['Mario', 'Bowser']}
>>> print(homeworlds['Mushroom Kingdom'])
['Mario', 'Bowser']
>>> print("{0}".format(', '.join(homeworlds['Mushroom Kingdom'])))
Mario, Bowser

在你的情况下交换for循环：'input'数据为'line'

创建列表的字典

6 个答案: