adding practice for data structures and collections

Author: BASNETANAMIKA

Self_Practice_Modules/2Collections.py

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+from collections import namedtuple,defaultdict
+
+import csv
+from urllib.request import  urlretrieve
+
+url = "https://raw.githubusercontent.com/sundeepblue/movie_rating_prediction/master/movie_metadata.csv"
+movies_csv = 'movie_metadata.csv'
+urlretrieve(url, 'movie_metadata.csv')
+#### Movie namedtuple
+Movie = namedtuple('Movie',['title', 'year','score'])
+
+
+def get_movies_by_director(data = movies_csv):
+    directors = defaultdict(list)
+    with open(data) as f:
+        for line in csv.DictReader(f):
+            try:
+                director = line['director_name']
+                movie = line['movie_title'].replace('\xa0', '')
+                year = int(line['title_year'])
+                score = float(line['imdb_score'])
+            except ValueError:
+                continue
+            m = Movie(title=movie, year=year, score=score)
+            directors[director].append(m)
+
+    return directors
+
+
+directors=get_movies_by_director()

Self_Practice_Modules/Dicts.py

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+# Given the provided cars dictionary:
+#
+# Get all Jeeps
+# Get the first car of every manufacturer.
+# Get all vehicles containing the string Trail in their names (should work for other grep too)
+# Sort the models (values) alphabetically
+
+
+cars = {
+    'Ford': ['Falcon', 'Focus', 'Festiva', 'Fairlane'],
+    'Holden': ['Commodore', 'Captiva', 'Barina', 'Trailblazer'],
+    'Nissan': ['Maxima', 'Pulsar', '350Z', 'Navara'],
+    'Honda': ['Civic', 'Accord', 'Odyssey', 'Jazz'],
+    'Jeep': ['Grand Cherokee', 'Cherokee', 'Trailhawk', 'Trackhawk']
+}
+
+
+def get_all_jeeps(cars=cars):
+    """return a comma  + space (', ') separated string of jeep models
+       (original order)"""
+
+    vehicles = cars['Jeep']
+    separator = ', '
+    separator.join(vehicles)
+    print(separator.join(vehicles))
+    return separator.join(vehicles)
+
+
+
+def get_first_model_each_manufacturer(cars=cars):
+    """return a list of matching models (original ordering)"""
+    first_model_list = []
+    for values in cars.values():
+        first_model_list.append(values[0])
+    print(first_model_list)
+    return first_model_list
+
+
+def get_all_matching_models(cars=cars, grep='trail'):
+    """return a list of all models containing the case insensitive
+       'grep' string which defaults to 'trail' for this exercise,
+       sort the resulting sequence alphabetically"""
+    import re
+    matching_models_list = []
+    for manufacturer, cars_list in cars.items():
+        for car in cars_list:
+            match_found = re.search(grep, car, re.IGNORECASE)
+            if match_found:
+                matching_models_list.append(car)
+    print(matching_models_list)
+    matching_models_list.sort()
+    return matching_models_list
+
+
+def sort_car_models(cars=cars):
+    """return a copy of the cars dict with the car models (values)
+    sorted alphabetically"""
+    for model, car_list in cars.items():
+        print(car_list)
+        car_list.sort()
+        # prints car_list.sort() returns None
+        cars[model] = car_list
+
+    print(cars)
+    return cars
+
+
+if __name__=="__main__":
+    # get_all_jeeps()
+    # get_first_model_each_manufacturer()
+    get_all_matching_models(grep="CO")
+    # get_all_matching_models()
+    # sort_car_models()

Self_Practice_Modules/Lists.py

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+numlist = [1,2,3,4,5]
+print(numlist)
+# reverse
+numlist.reverse()
+print(numlist)
+# sort values
+numlist.sort()
+print(numlist)
+
+for num in numlist:
+    print(str(num))
+
+mystring = "abracadabra"
+print(list(mystring))
+
+l = list(mystring)
+# return and remove the last element
+returned_var = l.pop()
+print("value returned due to pop {0}".format(returned_var))
+print("list now {0}".format(l))
+
+# insert value at the end
+l.insert(len(l), "a")
+print("reformed list {0}".format(l))
+
+del l[0]
+print("list after deletion {0}".format(l))
+
+l.insert(0, "a")
+print("l after insert is {0}".format(l))
+
+# pop using index
+a = l.pop(0)
+print("return value in pop {0}".format(a))
+
+new_tuple = tuple(mystring)
+print(new_tuple)
+
+for letter in new_tuple:
+    print(letter)