使用正则表达式提取数字

Question

I want to extract numbers using regular expression

df['price'][0] 

has

'[<em class="letter" id="infoJiga">3,402,000</em>]'

And I want to extract 3402000

How can I get this in pandas dataframe?

Answer 1

However the value is a string, try the below code.

#your code    
df['price'][0] returns  '[<em class="letter" id="infoJiga">3,402,000</em>]'

let us say this is x.

y = ''.join(c for c in x.split('>')[1]  if c.isdigit()).strip()
print (y)

output: 3402000

Hope it works.

Answer 2

The simplest regex assuming nothing about the environment may be ([\\d,]*) . Than you can pandas' to_numeric function.

Answer 3

Are all your values formatted the same way? If so, you can use a simple regular expression to extract the numeric values then convert them to int .

import pandas as pd
import re

test_data = ['[<em class="letter" id="infoJiga">3,402,000</em>]','[<em class="letter" id="infoJiga">3,401,000</em>]','[<em class="letter" id="infoJiga">3,400,000</em>]','[<em class="letter" id="infoJiga">2,000</em>]']
df = pd.DataFrame(test_data)
>>> df[0]
0    [<em class="letter" id="infoJiga">3,402,000</em>]
1    [<em class="letter" id="infoJiga">3,401,000</em>]
2    [<em class="letter" id="infoJiga">3,400,000</em>]
3        [<em class="letter" id="infoJiga">2,000</em>]
Name: 0, dtype: object

Define a method that extracts and returns to integer

def get_numeric(data):
    match = re.search('>(.+)<', data)
    if match:
        return int(match.group(1).replace(',',''))    
    return None

Apply it to DataFrame

df[1] = df[0].apply(get_numeric)
>>> df[1]
0    3402000
1    3401000
2    3400000
3       2000
Name: 1, dtype: int64