diff --git a/Week01/info_ertugrul_kose.py b/Week01/info_ertugrul_kose.py
new file mode 100644
index 00000000..301759a2
--- /dev/null
+++ b/Week01/info_ertugrul_kose.py
@@ -0,0 +1,2 @@
+student_id = "210316038"
+full_name = "Ertuğrul Köse"
diff --git a/Week02/types_ertugrul_kose.py b/Week02/types_ertugrul_kose.py
new file mode 100644
index 00000000..cf628a8f
--- /dev/null
+++ b/Week02/types_ertugrul_kose.py
@@ -0,0 +1,4 @@
+my_int = 9
+my_float = 11.4
+my_bool = True
+my_complex = 9j
diff --git a/Week03/pyramid_ertugrul_kose.py b/Week03/pyramid_ertugrul_kose.py
new file mode 100644
index 00000000..83d7da7d
--- /dev/null
+++ b/Week03/pyramid_ertugrul_kose.py
@@ -0,0 +1,6 @@
+def calculate_pyramid_height(blocks):
+    h = 0
+    while blocks > h:
+        h += 1
+        blocks -= h
+    return h
diff --git a/Week03/sequences_ertugrul_kose.py b/Week03/sequences_ertugrul_kose.py
new file mode 100644
index 00000000..c056a0d3
--- /dev/null
+++ b/Week03/sequences_ertugrul_kose.py
@@ -0,0 +1,34 @@
+def remove_duplicates(seq: list) -> list:
+    """
+    This function removes duplicates from a list.
+    """ 
+    unique = []
+    for x in seq:
+        if x not in unique:
+            unique.append(x)
+    return unique
+
+
+def list_counts(seq: list) -> dict:
+    """
+    This function counts the number of 
+    occurrences of each item in a list.
+    """
+    result = {}
+    for x in seq:
+        if x in result:
+            result[x] += 1
+        else:
+            result[x] = 1
+    return result
+
+
+def reverse_dict(d: dict) -> dict:
+    """
+    This function reverses the keys
+    and values of a dictionary
+    """
+    rev = {}
+    for k, v in d.items():
+        rev[v] = k
+    return rev
diff --git a/Week04/decorators_ertugrul_kose.py b/Week04/decorators_ertugrul_kose.py
new file mode 100644
index 00000000..4d49d388
--- /dev/null
+++ b/Week04/decorators_ertugrul_kose.py
@@ -0,0 +1,30 @@
+import tracemalloc as tm
+from time import time as current_time
+
+
+def performance(func):
+    """
+    Decorator that gathers call count, execution time and memory usage.
+    """
+
+    performance.count = 0
+    performance.time_total = 0.0
+    performance.mem_total = 0.0
+
+    def wrapper(*args, **kwargs):
+        tm.start()
+
+        start = current_time()
+        result = func(*args, **kwargs)
+        end = current_time()
+
+        mem_now, mem_peak = tm.get_traced_memory()
+        tm.stop()
+
+        performance.count += 1
+        performance.time_total += (end - start)
+        performance.mem_total += mem_peak
+
+        return result
+
+    return wrapper