fixed a doc string

Author: smartvinnetou

pandas/core/generic.py

@@ -9800,10 +9800,10 @@ def pct_change(
         Percentage change in French franc, Deutsche Mark, and Italian lira from
         1980-01-01 to 1980-03-01.
 
-        >>> df = pd.DataFrame({{
+        >>> df = pd.DataFrame({
         ...     'FR': [4.0405, 4.0963, 4.3149],
         ...     'GR': [1.7246, 1.7482, 1.8519],
-        ...     'IT': [804.74, 810.01, 860.13]}},
+        ...     'IT': [804.74, 810.01, 860.13]},
         ...     index=['1980-01-01', '1980-02-01', '1980-03-01'])
         >>> df
                         FR      GR      IT
@@ -9820,10 +9820,10 @@ def pct_change(
         Percentage of change in GOOG and APPL stock volume. Shows computing
         the percentage change between columns.
 
-        >>> df = pd.DataFrame({{
+        >>> df = pd.DataFrame({
         ...     '2016': [1769950, 30586265],
         ...     '2015': [1500923, 40912316],
-        ...     '2014': [1371819, 41403351]}},
+        ...     '2014': [1371819, 41403351]},
         ...     index=['GOOG', 'APPL'])
         >>> df
                   2016      2015      2014