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Method at

pandas/core/indexing.py:636–701  ·  view source on GitHub ↗

Access a single value for a row/column label pair. Similar to ``loc``, in that both provide label-based lookups. Use ``at`` if you only need to get or set a single value in a DataFrame or Series. Raises ------ KeyError If getting

(self)

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634
635 @property
636 def at(self) -> _AtIndexer:
637 """
638 Access a single value for a row/column label pair.
639
640 Similar to ``loc``, in that both provide label-based lookups. Use
641 ``at`` if you only need to get or set a single value in a DataFrame
642 or Series.
643
644 Raises
645 ------
646 KeyError
647 If getting a value and 'label' does not exist in a DataFrame or Series.
648
649 ValueError
650 If row/column label pair is not a tuple or if any label
651 from the pair is not a scalar for DataFrame.
652 If label is list-like (*excluding* NamedTuple) for Series.
653
654 See Also
655 --------
656 DataFrame.at : Access a single value for a row/column pair by label.
657 DataFrame.iat : Access a single value for a row/column pair by integer
658 position.
659 DataFrame.loc : Access a group of rows and columns by label(s).
660 DataFrame.iloc : Access a group of rows and columns by integer
661 position(s).
662 Series.at : Access a single value by label.
663 Series.iat : Access a single value by integer position.
664 Series.loc : Access a group of rows by label(s).
665 Series.iloc : Access a group of rows by integer position(s).
666
667 Notes
668 -----
669 See :ref:`Fast scalar value getting and setting <indexing.basics.get_value>`
670 for more details.
671
672 Examples
673 --------
674 >>> df = pd.DataFrame(
675 ... [[0, 2, 3], [0, 4, 1], [10, 20, 30]],
676 ... index=[4, 5, 6],
677 ... columns=["A", "B", "C"],
678 ... )
679 >>> df
680 A B C
681 4 0 2 3
682 5 0 4 1
683 6 10 20 30
684
685 Get value at specified row/column pair
686
687 >>> df.at[4, "B"]
688 np.int64(2)
689
690 Set value at specified row/column pair
691
692 >>> df.at[4, "B"] = 10
693 >>> df.at[4, "B"]

Callers 3

value_countsMethod · 0.80
test_ufunc_atMethod · 0.80
test_ufunc_raisesFunction · 0.80

Calls 1

_AtIndexerClass · 0.85

Tested by 2

test_ufunc_atMethod · 0.64
test_ufunc_raisesFunction · 0.64