Python: Pandas replace with regex

Question

I am trying to replace the data using Pandas. Following is my aim -

Remove alphabets from temperature and windspeed columns. 32 F will be replaced by 32 and 6 mph will be replaced by 6.
Convert all negative numbers in temperature and windspeed to NaN. -99999 will be converted to NaN.
Convert all 0 in event to No Event

Following is my code

import pandas as pd
import numpy as np
input_data = {'day': ['1/1/2017', '1/4/2017', '1/5/2017', '1/6/2017', 
                         '1/7/2017', '1/8/2017', '1/9/2017', '1/10/2017', '1/11/2017'],
             'temperature': ['32 F', -99999, 28, -99999, '32 C', '38 F', 35, 34, 40],
             'windspeed': ['6 mph', 9, -99999, 7, -88888, -99999, '10 kmph', 8, 12],
             'event': ['Rain', 'Sunny', 'Snow', 0, 'Rain', 'Sunny', 0, 'Cloudy', 'Sunny']
      }
weather2 = pd.DataFrame(input_data)
new_weather = weather2.replace({"temperature":{-99999: np.NaN,
                                          -88888: np.NaN,
                                          '[A-Za-z]':''},
                            "windspeed":{-99999: np.NaN,
                                          -88888: np.NaN,
                                          '[A-Za-z]':''},
                            "event":{0:'No Event'}},regex=True)

The output is as follows -

Only regex is changed. How can I combine regex with other replace?

Can you change picture of intput data to text? Please don't post images of code (or links to them) — jezrael
– jezrael, Commented Mar 20, 2018 at 12:42

BENY · Accepted Answer · 2018-03-20 12:46:27Z

1

Since in the beginning your column type should be string , all the number here should be string type

new_weather = weather2.replace({"temperature":{'-99999': np.NaN,
                                          '-88888': np.NaN,
                                          '[A-Za-z]':''},
                            "windspeed":{'-99999': np.NaN,
                                          '-88888': np.NaN,
                                          '[A-Za-z]':''},
                            "event":{'0':'No Event'}},regex=True)

If you want to know more information , try

weather2.applymap(type)

answered Mar 20, 2018 at 12:46

BENY

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2 Comments

Main Over a year ago

Thanks very much! Making all numbers as string solved the issue.

BENY Over a year ago

@Main yep , yw~ :-) happy coding

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