API Quick Reference#
Tip
Function names changed significantly with h3py
v4.0
to align with the C library: https://h3geo.org/docs/library/migration3.x/functions
We list the functions that are shared between the
provided APIs.
The APIs differ only in their input/output types
(e.g., int
vs. str
or list
vs numpy.array
).
These functions correspond to those explained in the H3 C library documentation, and should be generally aligned with the other language bindings.
Identification#
Validates an H3 cell (hexagon or pentagon). 


Identify if an H3 cell is a pentagon. 
Determine if cell has orientation "Class II" or "Class III". 


Validates an H3 unidirectional edge. 
Validates an H3 vertex. 
Index representation#

Converts an H3 64bit integer index to a hexadecimal string. 

Converts a hexadecimal string to an H3 64bit integer index. 
Cell properties#
Return all cells at resolution 0. 


Return all pentagons at a given resolution. 

Return the total number of cells (hexagons and pentagons) for the given resolution. 
Return the resolution of an H3 cell. 

Return the base cell number ( 
Geographic coordinates#
Functions relating H3 objects to geographic (lat/lng) coordinates.

Return the cell containing the (lat, lng) point for a given resolution. 
Return the center point of an H3 cell as a lat/lng pair. 


Compute the spherical surface area of a specific H3 cell. 

Compute the spherical length of a specific H3 edge. 
Return tuple of lat/lng pairs describing the cell boundary. 

Returns points representing the edge (line of points describing the boundary between two cells). 


Compute the spherical distance between two (lat, lng) points. 

Return the average area of an H3 hexagon for the given resolution. 

Return the average hexagon edge length for the given resolution. 
Hierarchical relationships#

Get the parent of a cell. 

Children of a cell as an unordered collection. 

Get the center child of a cell at some finer resolution. 

Number of children at resolution 

Child position index of given cell, with respect to its parent at 

Get child H3 cell from a parent cell, child resolution, and child position index. 

Compact a collection of H3 cells by combining smaller cells into larger cells, if all child cells are present. 

Reverse the 
Cell grid relationships#

Return unordered collection of cells with grid distance 

Return unordered collection of cells with grid distance 

Compute the grid distance between two cells. 

Returns 

Returns the ordered collection of cells denoting a minimumlength nonunique path between cells. 
Edges#

Create an H3 Index denoting a unidirectional edge. 
Return (origin, destination) tuple from H3 directed edge 

Origin cell from an H3 directed edge. 

Destination cell from an H3 directed edge. 


Return all directed edges starting from 
Vertexes#

Return a (specified) vertex of an H3 cell. 
Return a list of vertexes of an H3 cell. 

Return latitude and longitude of a vertex. 
Polygon interface#
The LatLngPoly
and LatLngMultiPoly
objects and their related functions allow users to represent (multi)polygons of lat/lng points and convert back and forth between H3 cells.
The objects and functions also compatible with the popular __geo_interface__
protocol, which is used by Python geospatial libraries like GeoPandas and many plotting libraries.
See the polygon tutorial for a walkthrough.
Tip
As with other h3py
functions, the polygon interface expects coordinate pairs in lat/lng order.
Note that this is reversed from __geo_interface__
objects, which are given in lng/lat order.
Polygon objects#

Abstract parent class of 

Container for loops of lat/lng points describing a polygon, possibly with holes. 

Container for multiple 
Conversion functions#

Translate from an 

Translate from 

Return the collection of H3 cells at a given resolution whose center points are contained within an 

Return an 

Convert from 

Convert from cells to a 
Specialized functions#
h3py
library#

Version numbers for the Python (wrapper) and C (wrapped) libraries. 
IJindexing#
Return icosahedron faces intersecting a given H3 cell. 


Return local (i,j) coordinates of cell 

Return cell at local (i,j) position relative to the 