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snippets/is_lower_case.md

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+### is_lower_case
+
+Checks if a string is lower case.
+
+Convert the given string to lower case, using `str.lower()` method and compare it to the original.
+
+```python
+def is_lower_case(str):
+    return str == str.lower()
+```
+
+```python
+is_lower_case('abc') # True
+is_lower_case('a3@$') # True
+is_lower_case('Ab4') # False
+```