from_ascii and from_file classmethods

esrimap/esrimap.py

@@ -100,6 +100,45 @@ nodata_value {self.nodata_value}
             header = header.replace("xllcenter", "xllcorner").replace("yllcenter", "yllcorner")
         return header
 
+    @classmethod
+    def from_ascii(cls, ascii_text: str) -> EsriAscii:
+        """Create an EsriAscii object from an ascii text. Data length must match rows and columns
+        (length of data = rows * columns)
+
+        :param ascii_text: The text (Should be an Esri Ascii raster formatted text)
+        :return: an EsriAscii map
+        """
+        lines = ascii_text.splitlines()
+        assert len(lines) > 6
+        _, s_ncols = lines[0].split(" ")
+        ncols = int(s_ncols)
+        _, s_nrows = lines[1].split(" ")
+        nrows = int(s_nrows)
+        alignment, s_xll = lines[2].split(" ")
+        xll = int(s_xll)
+        if alignment[3:] == "center":
+            coord = EsriCoordinateType.center
+        else:
+            coord = EsriCoordinateType.corner
+        _, s_yll = lines[3].split(" ")
+        yll = int(s_yll)
+        _, s_cellsize = lines[4].split(" ")
+        cellsize = int(s_cellsize)
+        _, s_nodata = lines[5].split(" ")
+        nodata = int(s_nodata)
+        s_data = " ".join(lines[6:])
+        data = np.array(s_data.split(" "), dtype=np.int32).reshape((nrows, ncols))
+        ascii_map = cls(rows=nrows,
+                        cols=ncols,
+                        cellsize=cellsize,
+                        data_array=data,
+                        nodata_value=nodata,
+                        coord_type=coord,
+                        )
+        ascii_map.xll = int(xll)
+        ascii_map.yll = int(yll)
+        return ascii_map
+
     def to_ascii(self) -> str:
         """Return the map as text
 
@@ -107,6 +146,12 @@ nodata_value {self.nodata_value}
         """
         return self.header + self.sdata
 
+    @classmethod
+    def from_file(cls, path: str) -> EsriAscii:
+        with open(path) as fp:
+            content = fp.read()
+        return cls.from_ascii(content)
+
     def to_file(self, path: str) -> None:
         """Write the ascii raster to a file.