Добавлены примеры и задание по типам коллекций

src-collections/statistics.py

@@ -0,0 +1,95 @@
+import collections
+import math
+import sys
+
+#Start 1st block
+Statistics = collections.namedtuple("Statistics",
+                                    "mean mode median std_dev")
+#End 1st block
+
+def main():
+    if len(sys.argv) == 1 or sys.argv[1] in {"-h", "--help"}:
+        print("usage: {0} file1 [file2 [... fileN]]".format(
+              sys.argv[0]))
+        sys.exit()
+
+    numbers = []
+    frequencies = collections.defaultdict(int)
+    for filename in sys.argv[1:]:
+        read_data(filename, numbers, frequencies)
+    if numbers:
+        statistics = calculate_statistics(numbers, frequencies)
+        print_results(len(numbers), statistics)
+    else:
+        print("no numbers found")
+
+
+def read_data(filename, numbers, frequencies):
+    with open(filename, encoding="ascii") as file:
+        for lino, line in enumerate(file, start=1):
+            for x in line.split():
+                try:
+                    number = float(x)
+                    numbers.append(number)
+                    frequencies[number] += 1
+                except ValueError as err:
+                    print("{filename}:{lino}: skipping {x}: {err}".format(
+                        **locals()))
+
+
+def calculate_statistics(numbers, frequencies):
+    mean = sum(numbers) / len(numbers)
+    mode = calculate_mode(frequencies, 3)
+    median = calculate_median(numbers)
+    std_dev = calculate_std_dev(numbers, mean)
+    return Statistics(mean, mode, median, std_dev)
+
+
+def calculate_mode(frequencies, maximum_modes):
+    highest_frequency = max(frequencies.values())
+    mode = [number for number, frequency in frequencies.items()
+            if frequency == highest_frequency]
+    if not (1 <= len(mode) <= maximum_modes):
+        mode = None
+    else:
+        mode.sort()
+    return mode
+
+
+def calculate_median(numbers):
+    numbers = sorted(numbers)
+    middle = len(numbers) // 2
+    median = numbers[middle]
+    if len(numbers) % 2 == 0:
+        median = (median + numbers[middle - 1]) / 2
+    return median
+
+
+def calculate_std_dev(numbers, mean):
+    total = 0
+    for number in numbers:
+        total += ((number - mean) ** 2)
+    variance = total / (len(numbers) - 1)
+    return math.sqrt(variance)
+
+
+def print_results(count, statistics):
+    real = "9.2f"
+
+    if statistics.mode is None:
+        modeline = ""
+    elif len(statistics.mode) == 1:
+        modeline = "mode      = {0:{fmt}}\n".format(statistics.mode[0], fmt=real)
+    else:
+        modeline = ("mode      = [" + ", ".join(["{0:.2f}".format(m)
+                    for m in statistics.mode]) + "]\n")
+
+    print("""\
+count     = {0:6}
+mean      = {mean:{fmt}}
+median    = {median:{fmt}}
+{1}\
+std. dev. = {std_dev:{fmt}}""".format(count, modeline, fmt=real, **statistics._asdict()))
+
+
+main()