add space around the equals sign

Author: echozzy629

pandas/core/groupby/groupby.py

@@ -1571,7 +1571,7 @@ def sample(groupby_result, size=None, frac=None, replace=False, weights=None):
         sample_keys=[]
         for i in sample:
             sample_keys.append(dictionary_keys[i])
-        sample_dictionary={key: value for key, value in groups_dictionary.items() if key in sample_keys}
+        sample_dictionary = {key: value for key, value in groups_dictionary.items() if key in sample_keys}
         return sample_dictionary