TST: fixed eng_formatter doctest for #42671

ci/code_checks.sh

@@ -121,6 +121,7 @@ if [[ -z "$CHECK" || "$CHECK" == "doctests" ]]; then
       pandas/io/parsers/ \
       pandas/io/sas/ \
       pandas/io/sql.py \
+      pandas/io/formats/format.py \
       pandas/tseries/
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 

pandas/io/formats/format.py

@@ -1956,16 +1956,14 @@ def __call__(self, num: int | float) -> str:
         """
         Formats a number in engineering notation, appending a letter
         representing the power of 1000 of the original number. Some examples:
-
-        >>> format_eng(0)       # for self.accuracy = 0
+        >>> format_eng = EngFormatter(accuracy=0, use_eng_prefix=True)
+        >>> format_eng(0)
         ' 0'
-
-        >>> format_eng(1000000) # for self.accuracy = 1,
-                                #     self.use_eng_prefix = True
+        >>> format_eng = EngFormatter(accuracy=1, use_eng_prefix=True)
+        >>> format_eng(1_000_000)
         ' 1.0M'
-
-        >>> format_eng("-1e-6") # for self.accuracy = 2
-                                #     self.use_eng_prefix = False
+        >>> format_eng = EngFormatter(accuracy=2, use_eng_prefix=False)
+        >>> format_eng("-1e-6")
         '-1.00E-06'
 
         @param num: the value to represent