TYPING: type hints for io.formats.latex (#27734)

Author: simonjayhawkins

pandas/io/formats/latex.py

@@ -1,11 +1,13 @@
 """
 Module for formatting output data in Latex.
 """
+from typing import IO, List, Optional, Tuple
+
 import numpy as np
 
 from pandas.core.dtypes.generic import ABCMultiIndex
 
-from pandas.io.formats.format import TableFormatter
+from pandas.io.formats.format import DataFrameFormatter, TableFormatter
 
 
 class LatexFormatter(TableFormatter):
@@ -28,12 +30,12 @@ class LatexFormatter(TableFormatter):
 
     def __init__(
         self,
-        formatter,
-        column_format=None,
-        longtable=False,
-        multicolumn=False,
-        multicolumn_format=None,
-        multirow=False,
+        formatter: DataFrameFormatter,
+        column_format: Optional[str] = None,
+        longtable: bool = False,
+        multicolumn: bool = False,
+        multicolumn_format: Optional[str] = None,
+        multirow: bool = False,
     ):
         self.fmt = formatter
         self.frame = self.fmt.frame
@@ -44,7 +46,7 @@ def __init__(
         self.multicolumn_format = multicolumn_format
         self.multirow = multirow
 
-    def write_result(self, buf):
+    def write_result(self, buf: IO[str]) -> None:
         """
         Render a DataFrame to a LaTeX tabular/longtable environment output.
         """
@@ -124,7 +126,7 @@ def pad_empties(x):
         if self.fmt.has_index_names and self.fmt.show_index_names:
             nlevels += 1
         strrows = list(zip(*strcols))
-        self.clinebuf = []
+        self.clinebuf = []  # type: List[List[int]]
 
         for i, row in enumerate(strrows):
             if i == nlevels and self.fmt.header:
@@ -186,7 +188,7 @@ def pad_empties(x):
         else:
             buf.write("\\end{longtable}\n")
 
-    def _format_multicolumn(self, row, ilevels):
+    def _format_multicolumn(self, row: List[str], ilevels: int) -> List[str]:
         r"""
         Combine columns belonging to a group to a single multicolumn entry
         according to self.multicolumn_format
@@ -227,7 +229,9 @@ def append_col():
             append_col()
         return row2
 
-    def _format_multirow(self, row, ilevels, i, rows):
+    def _format_multirow(
+        self, row: List[str], ilevels: int, i: int, rows: List[Tuple[str, ...]]
+    ) -> List[str]:
         r"""
         Check following rows, whether row should be a multirow
 
@@ -254,7 +258,7 @@ def _format_multirow(self, row, ilevels, i, rows):
                     self.clinebuf.append([i + nrow - 1, j + 1])
         return row
 
-    def _print_cline(self, buf, i, icol):
+    def _print_cline(self, buf: IO[str], i: int, icol: int) -> None:
         """
         Print clines after multirow-blocks are finished
         """