Map values of Series according to an input mapping or function.
Used for substituting each value in a Series with another value, that may be derived from a function, a dict or a Series.
Mapping correspondence.
If âignoreâ, propagate NaN values, without passing them to the mapping correspondence.
Same index as caller.
Notes
When arg is a dictionary, values in Series that are not in the dictionary (as keys) are converted to NaN. However, if the dictionary is a dict subclass that defines __missing__ (i.e. provides a method for default values), then this default is used rather than NaN.
Examples
>>> s = pd.Series(['cat', 'dog', np.nan, 'rabbit']) >>> s 0 cat 1 dog 2 NaN 3 rabbit dtype: object
map accepts a dict or a Series. Values that are not found in the dict are converted to NaN, unless the dict has a default value (e.g. defaultdict):
>>> s.map({'cat': 'kitten', 'dog': 'puppy'})
0 kitten
1 puppy
2 NaN
3 NaN
dtype: object
It also accepts a function:
>>> s.map('I am a {}'.format)
0 I am a cat
1 I am a dog
2 I am a nan
3 I am a rabbit
dtype: object
To avoid applying the function to missing values (and keep them as NaN) na_action='ignore' can be used:
>>> s.map('I am a {}'.format, na_action='ignore')
0 I am a cat
1 I am a dog
2 NaN
3 I am a rabbit
dtype: object
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4