如何使用字符串搜索变量？ / 你能在一个类中搜索一个变量吗？

Question

我正在从一个文件中获取一个团队的名称，我需要一种方法来找到一个同名的变量，所有团队名称变量都在一个名为 team 的类下，有没有办法搜索变量。我不知道用字典是否会更容易。蟒蛇

class team()...

Burnley = team("Burnley",[1, 0, 0, 1], True)
Southampton = team("Southampton", [1,2,1,0,0,0,1], True)
Swansea = team("Swansea",[1,2,1,1,1,2,1,1,0,0,0,0,0,0,3],True)

df = pd.read_csv("2016-17 testing.csv")
df =df[["Date","HomeTeam","AwayTeam","FTHG","FTAG","FTR"]]

for game in df.iterrows():

    home_team = df["HomeTeam"]
    away_team = df["AwayTeam"]

在这里我需要搜索主队并找到变量。使用 for 循环是因为我们将查看结果列表并将该数据用于某些用途。 谢谢

Answer 1

最好的方法是使用字典。

teams = {
    'Burnley': team("Burnley",[1, 0, 0, 1], True),
    'Southampton': team("Southampton", [1,2,1,0,0,0,1], True),
    'Swansea': team("Swansea",[1,2,1,1,1,2,1,1,0,0,0,0,0,0,3], True)
}

# and then simply fetch values from it
Burnley = teams['Burnley']

...
for idx, game in df.iterrows():
    home_team_name = game["HomeTeam"]  # Burnley let's assume
    home_team = teams[home_team_name] 
    ...

---

但是，如果您真的想要问题要求的内容，请继续阅读。

假设我有一个文件，sample.py

# sample.py
from pprint import pprint

variable = 'some value'
x = 20

pprint(globals())

输出：

$ python3 sample.py 
{'__annotations__': {},
 '__builtins__': <module 'builtins' (built-in)>,
 '__cached__': None,
 '__doc__': None,
 '__file__': 'sample.py',
 '__loader__': <_frozen_importlib_external.SourceFileLoader object at 0x7fccad01eb80>,
 '__name__': '__main__',
 '__package__': None,
 '__spec__': None,
 'pprint': <function pprint at 0x7fccacefdf70>,
 'variable': 'some value',
 'x': 20}

如您所见，所有定义的变量都将添加到globals()，它是dict，这意味着您可以从中获取值。

因此你可以做这样的事情

# sample.py
variable = 'some value'
x = 20

variable_name = 'variable'
number_name = 'x'

value_of_variable = globals().get(variable_name)
print(f'Value of variable = {value_of_variable}')

value_of_x = globals().get(number_name)
print(f'Value of x = {value_of_x}')

输出：

Value of variable = some value
Value of x = 20

---

所以对于你的情况，

...

for idx, game in df.iterrows():
    home_team_name = game["HomeTeam"]  # Burnley let's assume
    home_team = globals().get(home_team_name)  # would give you the value of the variable `Burnley` if it exists
    ...

如果您已经阅读了此处的全部答案，作为建议，我想补充一点，类名应以大写字母开头。 class Team: 而不是 class team: