Pandas DataFrame fillna() Method
Example
Replace NULL values with the number 222222:
In this example we use a .csv file called data.csv
import pandas as pd
df = pd.read_csv('data.csv')
newdf = df.fillna(222222)
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Definition and Usage
The fillna()
method replaces the NULL values
with a specified value.
The fillna()
method returns a new DataFrame
object unless the inplace
parameter is set to
True
, in that case the
fillna()
method does the replacing in the original DataFrame instead.
Syntax
dataframe.fillna(value, method, axis, inplace, limit, downcast)
Parameters
The axis
, method
,
inplace
,
limit
, downcast
parameters are
keyword arguments.
Parameter | Value | Description |
---|---|---|
value | Number String Dictionary Series DataFrame |
Required, Specifies the value to replace the NULL values with. This can also be values for the entire row or column. |
method | 'backfill' |
Optional, default None'. Specifies the method to use when replacing |
axis | 0 |
Optional, default 0. The axis to fill the NULL values along |
inplace | True |
Optional, default False. If True: the replacing is done on the current DataFrame. If False: returns a copy where the replacing is done. |
limit | NumberNone |
Optional, default None. Specifies the maximum number of NULL values to fill (if method is specified) |
downcast | DictionaryNone |
Optional, a dictionary of values to fill for specific data types |
Return Value
A DataFrame with the result, or None if the inplace parameter is set to True.