我在数据框中有两列,分别是字母和数字
我想关注
groupby
函数,它有助于分别识别项目1和项目2。我想在单个功能中执行此操作,请帮助.....
答案 0 :(得分:1)
您可以编写如下函数:
import pandas as pd
letter = ['A', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'F', 'G']
number = [10,11,5,6,15,15,20,20,25,28]
data = {'letter': letter, 'number': number}
df = pd.DataFrame(data)
def relationship(letter, number):
number_of_letters = {}
number_of_numbers = {}
relationship = []
for i in letter:
if i in number_of_letters:
number_of_letters[i] += 1
else:
number_of_letters[i] = 1
for i in number:
if i in number_of_numbers:
number_of_numbers[i] += 1
else:
number_of_numbers[i] = 1
for i in range(len(letter)):
if number_of_letters[letter[i]] == 1 and number_of_numbers[number[i]] == 1:
relationship.append('One to One')
elif number_of_letters[letter[i]] > 1 and number_of_numbers[number[i]] == 1:
relationship.append('One to Many')
elif number_of_letters[letter[i]] == 1 and number_of_numbers[number[i]] > 1:
relationship.append('Many to One')
elif number_of_letters[letter[i]] > 1 and number_of_numbers[number[i]] > 1:
relationship.append('Many to Many')
return relationship
df['relationship'] = relationship(letter, number)
答案 1 :(得分:1)
这可能是您的解决方案
import pandas as pd
d1 = ['A','A','B','C','D','E','F','G','F','G']
d2 = [10,11,5,6,15,15,20,20,25,28]
df = pd.DataFrame(list(zip(d1,d2)), columns = ['col1', 'col2'])
df['one to one'] = (df.groupby('col2')['col1'].transform(lambda x:x.nunique()==1) & df.groupby('col1')['col2'].transform(lambda x:x.nunique()==1))
df['many to one'] = (df.groupby('col2')['col1'].transform(lambda x:x.nunique()>1) & df.groupby('col1')['col2'].transform(lambda x:x.nunique()==1))
df['one to many'] = (df.groupby('col1')['col2'].transform(lambda x:x.nunique()>1) & df.groupby('col2')['col1'].transform(lambda x:x.nunique()==1))
df['many to many'] = (df.groupby('col1')['col2'].transform(lambda x:x.nunique()>1) & df.groupby('col2')['col1'].transform(lambda x:x.nunique()>1))
import numpy as np
conditions = [
(df['one to one'] == True), (df['one to many'] == True),(df['many to one'] == True),(df['many to many'] == True)]
choices = ['one to one', 'one to many', 'many to one','many to many']
df['relation'] = np.select(conditions, choices)
df.drop(['one to one', 'one to many', 'many to one','many to many'], axis = 1)