用于对导致 NameError 的术语进行分类的 Lambda 函数

Question

我正在尝试使用它们可能包含的一些正则表达式字符串按主题标记一些关键字。理想情况下，这将在数据框中附加一个“类别”列，其中包含它所属的标签或“其他”（如果没有找到）。

我试图标记的数据基本上如下所示：

| Keyword    |      Volume |
|:-----------|------------:|
| audi specs |        4000 |
| bmw width  |         170 |
| a45 bhp    |          30 |
| a1 length  |         210 |
| alfa co2   |          10 |

我目前得到的代码是：

import pandas as pd
import numpy as np
import re
from IPython.display import display

df = pd.read_csv("make-model-keywords.csv")
df = pd.DataFrame(df, columns=['Keyword', 'Volume','Keyword Difficulty','CPC (USD)', 'SERP Features'])

tags = [
{
    "name": "Dimensions",
    "regex": "dimension|width|height|length|size"
},
{
    "name": "MPG",
    "regex": "mpg|co2|emission|consumption|running|economy|fuel"
},
{
    "name": "Specs",
    "regex": "spec|specification|torque|bhp|weight|rpm|62|mph|kmh"
}
]

def basic_tagging(string, tags):
for tag in tags:
    if re.match(tag['regex'], row['Keyword']):
        return tag['name']
    else:
        return "other"

df['Category'] = df.apply(lambda x: basic_tagging(x['Keyword'], tags), axis=1)

但是它给了我以下错误：

---------------------------------------------------------------
NameError                     Traceback (most recent call last)
<ipython-input-71-31890ef48022> in <module>()
----> 1 df['Category'] = df.apply(lambda row: basic_tagging(row['Keyword'],         tags), axis=1)
  2 df.head()

~\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\frame.py in apply(self, func, axis, broadcast, raw, reduce, result_type, args, **kwds)
   6012                          args=args,
   6013                          kwds=kwds)
-> 6014         return op.get_result()
   6015 
   6016     def applymap(self, func):

~\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\apply.py in get_result(self)
    140             return self.apply_raw()
    141 
--> 142         return self.apply_standard()
    143 
    144     def apply_empty_result(self):

~\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\apply.py in apply_standard(self)
    246 
    247         # compute the result using the series generator
--> 248         self.apply_series_generator()
    249 
    250         # wrap results

~\AppData\Local\Continuum\anaconda3\lib\site-packages\pandas\core\apply.py in apply_series_generator(self)
    275             try:
    276                 for i, v in enumerate(series_gen):
--> 277                     results[i] = self.f(v)
    278                     keys.append(v.name)
    279             except Exception as e:

<ipython-input-71-31890ef48022> in <lambda>(row)
----> 1 df['Category'] = df.apply(lambda row: basic_tagging(row['Keyword'], tags), axis=1)
  2 df.head()

<ipython-input-68-1867110ca579> in basic_tagging(string, tags)
      1 def basic_tagging(string, tags):
      2     for tag in tags:
----> 3         if re.match(tag['regex'], row['Keyword']):
      4             return tag['name']
      5         else:

NameError: ("name 'row' is not defined", 'occurred at index 0')

我是否遗漏了一些显而易见的东西？

Answer 1

把你的函数改成这样：

def basic_tagging(row):
    for tag in tags:
        if re.match(tag['regex'], row['Keyword']):
            return tag['name']
        else:
            return "other"

然后：

df['Category'] = df.apply(basic_tagging, axis=1)