Pandas

Question

假设我有一个这样的 DataFrame：

df = pd.DataFrame({'consumption':['squirrel eats apple', 'monkey eats apple', 
                                  'monkey eats banana', 'badger eats banana'], 
                   'food':['apple', 'apple', 'banana', 'banana'], 
                   'creature':['squirrel', 'badger', 'monkey', 'elephant']})

    consumption creature    food
0   squirrel eats apple squirrel    apple
1   monkey eats apple   badger  apple
2   monkey eats banana  monkey  banana
3   badger eats banana  elephant    banana

我想找到 'creature' 和 'food' 在 'consumption' 列中组合出现的行，即如果 apple 和 squirrel 一起出现，则 True 但如果 Apple 与 Elephant 一起出现这是假的。同样，如果 Monkey & Banana 一起出现，则为 True，但 Monkey-Apple 为 false。

我尝试的方法类似于：

creature_list = list(df['creature'])
creature_list = '|'.join(map(str, creature_list))

food_list = list(df['food'])
food_list = '|'.join(map(str, food_list))

np.where((df['consumption'].str.contains('('+creature_list+')', case = False)) 
          & (df['consumption'].str.contains('('+food_list+')', case = False)), 1, 0)

但这不起作用，因为我在所有情况下都得到 True。

如何检查字符串对？

Answer 1

我相信有更好的方法来做到这一点。但这是一种方式。

import pandas as pd
import re

df = pd.DataFrame({'consumption':['squirrel eats apple', 'monkey eats apple', 'monkey eats banana', 'badger eats banana'], 'food':['apple', 'apple', 'banana', 'banana'], 'creature':['squirrel', 'badger', 'monkey', 'elephant']})

test = []
for i in range(len(df.consumption)):
    test.append(bool(re.search(df.creature[i],df.consumption[i])) & bool((re.search(df.food[i], df.consumption[i]))))
df['test'] = test

Answer 2

这是一种可行的方法：

def match_consumption(r):
    if (r['creature'] in r['consumption']) and (r['food'] in r['consumption']):
        return True
    else:
        return False

df['match'] = df.apply(match_consumption, axis=1)
df

           consumption  creature    food  match
0  squirrel eats apple  squirrel   apple   True
1    monkey eats apple    badger   apple  False
2   monkey eats banana    monkey  banana   True
3   badger eats banana  elephant  banana  False

Answer 3

检查字符串是否相等太简单了？您可以测试字符串 <creature> eats <food> 是否等于 consumption 列中的相应值：

(df.consumption == df.creature + " eats " + df.food)

Pandas - 检查字符串列是否包含一对字符串

Pandas - check if a string column contains a pair of strings

python

string

boolean-expression