6.9. DataFrame Getitem
DataFrame[column]- select a columnDataFrame[[column1, column2, ...]]- select multiple columnsDataFrame[start:stop]- slice rowsDataFrame[start:stop:step]- slice rows
6.9.1. SetUp
>>> import pandas as pd
>>>
>>> df = pd.DataFrame([
... {'firstname': 'Alice', 'lastname': 'Apricot', 'age': 30},
... {'firstname': 'Bob', 'lastname': 'Blackthorn', 'age': 31},
... {'firstname': 'Carol', 'lastname': 'Corn', 'age': 32},
... ], index=['a', 'b', 'c'])
>>> df
firstname lastname age
a Alice Apricot 30
b Bob Blackthorn 31
c Carol Corn 32
6.9.2. Columns
DataFrame[column]- select a columnDataFrame[[column1, column2, ...]]- select multiple columns
>>> df['firstname']
a Alice
b Bob
c Carol
Name: firstname, dtype: str
>>> df[['firstname', 'lastname']]
firstname lastname
a Alice Apricot
b Bob Blackthorn
c Carol Corn
6.9.3. Rows
DataFrame[start:stop]- slice rowsDataFrame[start:stop:step]- slice rows
>>> df[0:2]
firstname lastname age
a Alice Apricot 30
b Bob Blackthorn 31
>>> df[::2]
firstname lastname age
a Alice Apricot 30
c Carol Corn 32
6.9.4. Errors
>>> df['a']
Traceback (most recent call last):
KeyError: 'a'
>>> df[0]
Traceback (most recent call last):
KeyError: 0
>>> df[[0,1]]
Traceback (most recent call last):
KeyError: "None of [Index([0, 1], dtype='int64')] are in the [columns]"