Indexing

Index

Many of these methods or variants thereof are available on the objects that contain an index (Series/DataFrame) and those should most likely be used before calling these methods directly.

Index

Immutable ndarray implementing an ordered, sliceable set.

Properties

Index.values

Return an array representing the data in the Index.

Index.is_monotonic

Alias for is_monotonic_increasing.

Index.is_monotonic_increasing

Return if the index is monotonic increasing (only equal or increasing) values.

Index.is_monotonic_decreasing

Return if the index is monotonic decreasing (only equal or decreasing) values.

Index.is_unique

Return if the index has unique values.

Index.has_duplicates

Index.hasnans

Return if I have any nans; enables various perf speedups.

Index.dtype

Return the dtype object of the underlying data.

Index.dtype_str

Return the dtype str of the underlying data.

Index.inferred_type

Return a string of the type inferred from the values.

Index.is_all_dates

Index.shape

Return a tuple of the shape of the underlying data.

Index.name

Index.names

Index.nbytes

Return the number of bytes in the underlying data.

Index.ndim

Number of dimensions of the underlying data, by definition 1.

Index.size

Return the number of elements in the underlying data.

Index.empty

Index.strides

(DEPRECATED) Return the strides of the underlying data.

Index.itemsize

(DEPRECATED) Return the size of the dtype of the item of the underlying data.

Index.base

(DEPRECATED) Return the base object if the memory of the underlying data is shared.

Index.T

Return the transpose, which is by definition self.

Index.memory_usage(self[, deep])

Memory usage of the values

Modifying and Computations

Index.all(self, \*args, \*\*kwargs)

Return whether all elements are True.

Index.any(self, \*args, \*\*kwargs)

Return whether any element is True.

Index.argmin(self[, axis, skipna])

Return a ndarray of the minimum argument indexer.

Index.argmax(self[, axis, skipna])

Return an ndarray of the maximum argument indexer.

Index.copy(self[, name, deep, dtype])

Make a copy of this object.

Index.delete(self, loc)

Make new Index with passed location(-s) deleted.

Index.drop(self, labels[, errors])

Make new Index with passed list of labels deleted.

Index.drop_duplicates(self[, keep])

Return Index with duplicate values removed.

Index.duplicated(self[, keep])

Indicate duplicate index values.

Index.equals(self, other)

Determine if two Index objects contain the same elements.

Index.factorize(self[, sort, na_sentinel])

Encode the object as an enumerated type or categorical variable.

Index.identical(self, other)

Similar to equals, but check that other comparable attributes are also equal.

Index.insert(self, loc, item)

Make new Index inserting new item at location.

Index.is_(self, other)

More flexible, faster check like is but that works through views.

Index.is_boolean(self)

Index.is_categorical(self)

Check if the Index holds categorical data.

Index.is_floating(self)

Index.is_integer(self)

Index.is_interval(self)

Index.is_mixed(self)

Index.is_numeric(self)

Index.is_object(self)

Index.min(self[, axis, skipna])

Return the minimum value of the Index.

Index.max(self[, axis, skipna])

Return the maximum value of the Index.

Index.reindex(self, target[, method, level, …])

Create index with target’s values (move/add/delete values as necessary).

Index.rename(self, name[, inplace])

Alter Index or MultiIndex name.

Index.repeat(self, repeats[, axis])

Repeat elements of a Index.

Index.where(self, cond[, other])

Return an Index of same shape as self and whose corresponding entries are from self where cond is True and otherwise are from other.

Index.take(self, indices[, axis, …])

Return a new Index of the values selected by the indices.

Index.putmask(self, mask, value)

Return a new Index of the values set with the mask.

Index.unique(self[, level])

Return unique values in the index.

Index.nunique(self[, dropna])

Return number of unique elements in the object.

Index.value_counts(self[, normalize, sort, …])

Return a Series containing counts of unique values.

Compatibility with MultiIndex

Index.set_names(self, names[, level, inplace])

Set Index or MultiIndex name.

Index.is_lexsorted_for_tuple(self, tup)

Index.droplevel(self[, level])

Return index with requested level(s) removed.

Missing Values

Index.fillna(self[, value, downcast])

Fill NA/NaN values with the specified value

Index.dropna(self[, how])

Return Index without NA/NaN values

Index.isna(self)

Detect missing values.

Index.notna(self)

Detect existing (non-missing) values.

Conversion

Index.astype(self, dtype[, copy])

Create an Index with values cast to dtypes.

Index.item(self)

Return the first element of the underlying data as a python scalar.

Index.map(self, mapper[, na_action])

Map values using input correspondence (a dict, Series, or function).

Index.ravel(self[, order])

Return an ndarray of the flattened values of the underlying data.

Index.to_list(self)

Return a list of the values.

Index.to_native_types(self[, slicer])

Format specified values of self and return them.

Index.to_series(self[, index, name])

Create a Series with both index and values equal to the index keys useful with map for returning an indexer based on an index.

Index.to_frame(self[, index, name])

Create a DataFrame with a column containing the Index.

Index.view(self[, cls])

Sorting

Index.argsort(self, \*args, \*\*kwargs)

Return the integer indices that would sort the index.

Index.searchsorted(self, value[, side, sorter])

Find indices where elements should be inserted to maintain order.

Index.sort_values(self[, return_indexer, …])

Return a sorted copy of the index.

Time-specific operations

Index.shift(self[, periods, freq])

Shift index by desired number of time frequency increments.

Combining / joining / set operations

Index.append(self, other)

Append a collection of Index options together.

Index.join(self, other[, how, level, …])

Compute join_index and indexers to conform data structures to the new index.

Index.intersection(self, other[, sort])

Form the intersection of two Index objects.

Index.union(self, other[, sort])

Form the union of two Index objects.

Index.difference(self, other[, sort])

Return a new Index with elements from the index that are not in other.

Index.symmetric_difference(self, other[, …])

Compute the symmetric difference of two Index objects.

Selecting

Index.asof(self, label)

Return the label from the index, or, if not present, the previous one.

Index.asof_locs(self, where, mask)

Find the locations (indices) of the labels from the index for every entry in the where argument.

Index.contains(self, key)

Return a boolean indicating whether the provided key is in the index.

Index.get_duplicates(self)

(DEPRECATED) Extract duplicated index elements.

Index.get_indexer(self, target[, method, …])

Compute indexer and mask for new index given the current index.

Index.get_indexer_for(self, target, \*\*kwargs)

Guaranteed return of an indexer even when non-unique.

Index.get_indexer_non_unique(self, target)

Compute indexer and mask for new index given the current index.

Index.get_level_values(self, level)

Return an Index of values for requested level.

Index.get_loc(self, key[, method, tolerance])

Get integer location, slice or boolean mask for requested label.

Index.get_slice_bound(self, label, side, kind)

Calculate slice bound that corresponds to given label.

Index.get_value(self, series, key)

Fast lookup of value from 1-dimensional ndarray.

Index.get_values(self)

Return Index data as an numpy.ndarray.

Index.set_value(self, arr, key, value)

Fast lookup of value from 1-dimensional ndarray.

Index.isin(self, values[, level])

Return a boolean array where the index values are in values.

Index.slice_indexer(self[, start, end, …])

For an ordered or unique index, compute the slice indexer for input labels and step.

Index.slice_locs(self[, start, end, step, kind])

Compute slice locations for input labels.

Numeric Index

RangeIndex

Immutable Index implementing a monotonic integer range.

Int64Index

Immutable ndarray implementing an ordered, sliceable set.

UInt64Index

Immutable ndarray implementing an ordered, sliceable set.

Float64Index

Immutable ndarray implementing an ordered, sliceable set.

RangeIndex.from_range(data[, name, dtype])

Create RangeIndex from a range object.

CategoricalIndex

CategoricalIndex

Index based on an underlying Categorical.

Categorical Components

CategoricalIndex.codes

CategoricalIndex.categories

CategoricalIndex.ordered

CategoricalIndex.rename_categories(self, …)

Rename categories.

CategoricalIndex.reorder_categories(self, …)

Reorder categories as specified in new_categories.

CategoricalIndex.add_categories(self, …)

Add new categories.

CategoricalIndex.remove_categories(self, …)

Remove the specified categories.

CategoricalIndex.remove_unused_categories(…)

Remove categories which are not used.

CategoricalIndex.set_categories(self, …)

Set the categories to the specified new_categories.

CategoricalIndex.as_ordered(self, \*args, …)

Set the Categorical to be ordered.

CategoricalIndex.as_unordered(self, \*args, …)

Set the Categorical to be unordered.

Modifying and Computations

CategoricalIndex.map(self, mapper)

Map values using input correspondence (a dict, Series, or function).

CategoricalIndex.equals(self, other)

Determine if two CategorialIndex objects contain the same elements.

IntervalIndex

IntervalIndex

Immutable index of intervals that are closed on the same side.

IntervalIndex Components

IntervalIndex.from_arrays(left, right[, …])

Construct from two arrays defining the left and right bounds.

IntervalIndex.from_tuples(data[, closed, …])

Construct an IntervalIndex from an array-like of tuples

IntervalIndex.from_breaks(breaks[, closed, …])

Construct an IntervalIndex from an array of splits.

IntervalIndex.contains(self, key)

Return a boolean indicating if the key is IN the index

IntervalIndex.left

Return the left endpoints of each Interval in the IntervalIndex as an Index

IntervalIndex.right

Return the right endpoints of each Interval in the IntervalIndex as an Index

IntervalIndex.mid

Return the midpoint of each Interval in the IntervalIndex as an Index

IntervalIndex.closed

Whether the intervals are closed on the left-side, right-side, both or neither

IntervalIndex.length

Return an Index with entries denoting the length of each Interval in the IntervalIndex

IntervalIndex.values

Return the IntervalIndex’s data as an IntervalArray.

IntervalIndex.is_non_overlapping_monotonic

Return True if the IntervalIndex is non-overlapping (no Intervals share points) and is either monotonic increasing or monotonic decreasing, else False

IntervalIndex.is_overlapping

Return True if the IntervalIndex has overlapping intervals, else False.

IntervalIndex.get_loc(self, key[, method])

Get integer location, slice or boolean mask for requested label.

IntervalIndex.get_indexer(self, target[, …])

Compute indexer and mask for new index given the current index.

IntervalIndex.set_closed(self, closed)

Return an IntervalIndex identical to the current one, but closed on the specified side

IntervalIndex.overlaps(self, other)

Check elementwise if an Interval overlaps the values in the IntervalIndex.

IntervalIndex.to_tuples(self[, na_tuple])

Return an Index of tuples of the form (left, right)

MultiIndex

MultiIndex

A multi-level, or hierarchical, index object for pandas objects.

IndexSlice

Create an object to more easily perform multi-index slicing

MultiIndex Constructors

MultiIndex.from_arrays(arrays[, sortorder, …])

Convert arrays to MultiIndex.

MultiIndex.from_tuples(tuples[, sortorder, …])

Convert list of tuples to MultiIndex.

MultiIndex.from_product(iterables[, …])

Make a MultiIndex from the cartesian product of multiple iterables.

MultiIndex.from_frame(df[, sortorder, names])

Make a MultiIndex from a DataFrame.

MultiIndex Properties

MultiIndex.names

Names of levels in MultiIndex

MultiIndex.levels

MultiIndex.codes

MultiIndex.nlevels

Integer number of levels in this MultiIndex.

MultiIndex.levshape

A tuple with the length of each level.

MultiIndex Components

MultiIndex.set_levels(self, levels[, level, …])

Set new levels on MultiIndex.

MultiIndex.set_codes(self, codes[, level, …])

Set new codes on MultiIndex.

MultiIndex.to_hierarchical(self, n_repeat[, …])

(DEPRECATED) Return a MultiIndex reshaped to conform to the shapes given by n_repeat and n_shuffle.

MultiIndex.to_flat_index(self)

Convert a MultiIndex to an Index of Tuples containing the level values.

MultiIndex.to_frame(self[, index, name])

Create a DataFrame with the levels of the MultiIndex as columns.

MultiIndex.is_lexsorted(self)

Return True if the codes are lexicographically sorted

MultiIndex.sortlevel(self[, level, …])

Sort MultiIndex at the requested level.

MultiIndex.droplevel(self[, level])

Return index with requested level(s) removed.

MultiIndex.swaplevel(self[, i, j])

Swap level i with level j.

MultiIndex.reorder_levels(self, order)

Rearrange levels using input order.

MultiIndex.remove_unused_levels(self)

Create a new MultiIndex from the current that removes unused levels, meaning that they are not expressed in the labels.

MultiIndex Selecting

MultiIndex.get_loc(self, key[, method])

Get location for a label or a tuple of labels as an integer, slice or boolean mask.

MultiIndex.get_loc_level(self, key[, level, …])

Get both the location for the requested label(s) and the resulting sliced index.

MultiIndex.get_indexer(self, target[, …])

Compute indexer and mask for new index given the current index.

MultiIndex.get_level_values(self, level)

Return vector of label values for requested level, equal to the length of the index.

DatetimeIndex

DatetimeIndex

Immutable ndarray of datetime64 data, represented internally as int64, and which can be boxed to Timestamp objects that are subclasses of datetime and carry metadata such as frequency information.

Time/Date Components

DatetimeIndex.year

The year of the datetime.

DatetimeIndex.month

The month as January=1, December=12.

DatetimeIndex.day

The days of the datetime.

DatetimeIndex.hour

The hours of the datetime.

DatetimeIndex.minute

The minutes of the datetime.

DatetimeIndex.second

The seconds of the datetime.

DatetimeIndex.microsecond

The microseconds of the datetime.

DatetimeIndex.nanosecond

The nanoseconds of the datetime.

DatetimeIndex.date

Returns numpy array of python datetime.date objects (namely, the date part of Timestamps without timezone information).

DatetimeIndex.time

Returns numpy array of datetime.time.

DatetimeIndex.timetz

Returns numpy array of datetime.time also containing timezone information.

DatetimeIndex.dayofyear

The ordinal day of the year.

DatetimeIndex.weekofyear

The week ordinal of the year.

DatetimeIndex.week

The week ordinal of the year.

DatetimeIndex.dayofweek

The day of the week with Monday=0, Sunday=6.

DatetimeIndex.weekday

The day of the week with Monday=0, Sunday=6.

DatetimeIndex.quarter

The quarter of the date.

DatetimeIndex.tz

DatetimeIndex.freq

Return the frequency object if it is set, otherwise None.

DatetimeIndex.freqstr

Return the frequency object as a string if it is set, otherwise None.

DatetimeIndex.is_month_start

Indicates whether the date is the first day of the month.

DatetimeIndex.is_month_end

Indicates whether the date is the last day of the month.

DatetimeIndex.is_quarter_start

Indicator for whether the date is the first day of a quarter.

DatetimeIndex.is_quarter_end

Indicator for whether the date is the last day of a quarter.

DatetimeIndex.is_year_start

Indicate whether the date is the first day of a year.

DatetimeIndex.is_year_end

Indicate whether the date is the last day of the year.

DatetimeIndex.is_leap_year

Boolean indicator if the date belongs to a leap year.

DatetimeIndex.inferred_freq

Tryies to return a string representing a frequency guess, generated by infer_freq.

Selecting

DatetimeIndex.indexer_at_time(self, time[, asof])

Return index locations of index values at particular time of day (e.g.

DatetimeIndex.indexer_between_time(self, …)

Return index locations of values between particular times of day (e.g., 9:00-9:30AM).

Time-specific operations

DatetimeIndex.normalize(self, \*args, \*\*kwargs)

Convert times to midnight.

DatetimeIndex.strftime(self, \*args, \*\*kwargs)

Convert to Index using specified date_format.

DatetimeIndex.snap(self[, freq])

Snap time stamps to nearest occurring frequency

DatetimeIndex.tz_convert(self, \*args, …)

Convert tz-aware Datetime Array/Index from one time zone to another.

DatetimeIndex.tz_localize(self, \*args, …)

Localize tz-naive Datetime Array/Index to tz-aware Datetime Array/Index.

DatetimeIndex.round(self, \*args, \*\*kwargs)

Perform round operation on the data to the specified freq.

DatetimeIndex.floor(self, \*args, \*\*kwargs)

Perform floor operation on the data to the specified freq.

DatetimeIndex.ceil(self, \*args, \*\*kwargs)

Perform ceil operation on the data to the specified freq.

DatetimeIndex.month_name(self, \*args, …)

Return the month names of the DateTimeIndex with specified locale.

DatetimeIndex.day_name(self, \*args, \*\*kwargs)

Return the day names of the DateTimeIndex with specified locale.

Conversion

DatetimeIndex.to_period(self, \*args, \*\*kwargs)

Cast to PeriodArray/Index at a particular frequency.

DatetimeIndex.to_perioddelta(self, \*args, …)

Calculate TimedeltaArray of difference between index values and index converted to PeriodArray at specified freq.

DatetimeIndex.to_pydatetime(self, \*args, …)

Return Datetime Array/Index as object ndarray of datetime.datetime objects

DatetimeIndex.to_series(self[, keep_tz, …])

Create a Series with both index and values equal to the index keys useful with map for returning an indexer based on an index

DatetimeIndex.to_frame(self[, index, name])

Create a DataFrame with a column containing the Index.

TimedeltaIndex

TimedeltaIndex

Immutable ndarray of timedelta64 data, represented internally as int64, and which can be boxed to timedelta objects

Components

TimedeltaIndex.days

Number of days for each element.

TimedeltaIndex.seconds

Number of seconds (>= 0 and less than 1 day) for each element.

TimedeltaIndex.microseconds

Number of microseconds (>= 0 and less than 1 second) for each element.

TimedeltaIndex.nanoseconds

Number of nanoseconds (>= 0 and less than 1 microsecond) for each element.

TimedeltaIndex.components

Return a dataframe of the components (days, hours, minutes, seconds, milliseconds, microseconds, nanoseconds) of the Timedeltas.

TimedeltaIndex.inferred_freq

Tryies to return a string representing a frequency guess, generated by infer_freq.

Conversion

TimedeltaIndex.to_pytimedelta(self, \*args, …)

Return Timedelta Array/Index as object ndarray of datetime.timedelta objects.

TimedeltaIndex.to_series(self[, index, name])

Create a Series with both index and values equal to the index keys useful with map for returning an indexer based on an index.

TimedeltaIndex.round(self, freq[, …])

Perform round operation on the data to the specified freq.

TimedeltaIndex.floor(self, freq[, …])

Perform floor operation on the data to the specified freq.

TimedeltaIndex.ceil(self, freq[, ambiguous, …])

Perform ceil operation on the data to the specified freq.

TimedeltaIndex.to_frame(self[, index, name])

Create a DataFrame with a column containing the Index.

PeriodIndex

PeriodIndex

Immutable ndarray holding ordinal values indicating regular periods in time such as particular years, quarters, months, etc.

Properties

PeriodIndex.day

The days of the period

PeriodIndex.dayofweek

The day of the week with Monday=0, Sunday=6

PeriodIndex.dayofyear

The ordinal day of the year

PeriodIndex.days_in_month

The number of days in the month

PeriodIndex.daysinmonth

The number of days in the month

PeriodIndex.end_time

PeriodIndex.freq

Return the frequency object if it is set, otherwise None.

PeriodIndex.freqstr

Return the frequency object as a string if it is set, otherwise None.

PeriodIndex.hour

The hour of the period

PeriodIndex.is_leap_year

Logical indicating if the date belongs to a leap year

PeriodIndex.minute

The minute of the period

PeriodIndex.month

The month as January=1, December=12

PeriodIndex.quarter

The quarter of the date

PeriodIndex.qyear

PeriodIndex.second

The second of the period

PeriodIndex.start_time

PeriodIndex.week

The week ordinal of the year

PeriodIndex.weekday

The day of the week with Monday=0, Sunday=6

PeriodIndex.weekofyear

The week ordinal of the year

PeriodIndex.year

The year of the period

Methods

PeriodIndex.asfreq(self, \*args, \*\*kwargs)

Convert the Period Array/Index to the specified frequency freq.

PeriodIndex.strftime(self, \*args, \*\*kwargs)

Convert to Index using specified date_format.

PeriodIndex.to_timestamp(self, \*args, …)

Cast to DatetimeArray/Index.

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