从拆分字符串列创建新列

Question

我想做的是创建新的列来捕获字符串中的每个单词。例如：

df

Col1        Col2  
 38       'My Name is John'
 11       'Hello friend'
 134      'My favorite city is New Orleans'

所需df：

Col1    Col2    Col3    Col4    Col5    Col6    Col7
38      'My'   'Name'    'is'   'John'   NA      NA
11     'Hello' 'friend'   NA     NA      NA      NA
134     'My'  'favorite' 'city' 'is'    'New' 'Orleans'

有人对此有什么想法吗？谢谢

Answer 1

您可以将Col2转换为包含单词列表的序列，然后将该序列转换回数据帧

import pandas as pd

# OPs data
x = ['My Name is John', 'Hello friend', 'My favorite city is New Orleans']
df = pd.DataFrame(x, columns=['Col2'])

# convert to series with lists
s = df['Col2'].apply(lambda x: x.split())

# lists to dataframe
df_new = pd.DataFrame(item for item in s)

Answer 2

方法str.split将在单词列表的列中拆分字符串。然后，您可以填充列表，使其具有相同的长度，并由此创建新的数据帧：

words = df.text.str.split()
maxlen = words.map(len).max()

def pad_list(l):
    return l + [None] * (maxlen - len(l))

words = pd.DataFrame(np.stack(words.map(pad_list), axis=0))

Answer 3

您可以使用以下方法创建它：

import pandas as pd

df = pd.DataFrame({'Col1': [38, 11, 134], 
                    'Col2':['My Name is John', 'Hello friend', 'My favorite city is New Orleans']})
 

df1 = df.Col2.str.split(expand=True) 

df1.columns = ['Col1', 'Col2', 'Col3', 'Col4', 'Col5', 'Col6']