fix blank spaces not being caught in *.pyx

refs #21980

Author: illegalnumbers

ci/lint.sh

@@ -49,6 +49,11 @@ if [ "$LINT" ]; then
     if [ $? -ne "0" ]; then
         RET=1
     fi
+
+    if [[ -n $(find **/*.pyx -type f -exec egrep -l " +$" {} \;) ]]
+    then
+        RET=1
+    fi
     echo "Linting *.pyx DONE"
 
     echo "Linting *.pxi.in"
@@ -173,7 +178,7 @@ if [ "$LINT" ]; then
         RET=1
     fi
     echo "Check for old-style classes DONE"
-    
+
     echo "Check for backticks incorrectly rendering because of missing spaces"
     grep -R --include="*.rst" -E "[a-zA-Z0-9]\`\`?[a-zA-Z0-9]" doc/source/
 

pandas/_libs/tslibs/period.pyx

@@ -1538,7 +1538,7 @@ cdef class _Period(object):
         See Also
         --------
         Period.year : Return the calendar year of the period.
-        
+
         Examples
         --------
         If the natural and fiscal year are the same, `qyear` and `year` will