updated contents from Atlas repo

sequences/metro_areas.py

@@ -0,0 +1,49 @@
+FILENAME = 'metro_areas.txt'
+
+class MetroArea:
+
+    def __init__(self, name, country, pop, pop_change, area):
+        self.name = name
+        self.country = country
+        self.pop = pop
+        self.pop_change = pop_change
+        self.area = area
+
+    def __repr__(self):
+        return '{0.name}, {0.country} ({0.pop})'.format(self)
+
+    def density(self):
+        return self.pop / self.area
+
+
+def load():
+    metro_areas = []
+    with open(FILENAME, encoding='utf-8') as text:
+        for line in text:
+            if line.startswith('#'):
+                continue
+            # Country Name Rank Population Yr_change % Area(km2) Pop/km2
+            country, name, _, pop, pop_change, _, area, _ = line.split('\t')
+            pop = float(pop.replace(',', ''))
+            pop_change = float(pop_change)
+            area = float(area)
+            metro_areas.append((name, country, pop, pop_change, area))
+    return metro_areas
+
+
+def list(metro_areas):
+    print('{:^18} {:>6} {:>4} {:>6}'.format('name', 'cc', 'pop', 'chg', 'area'))
+    for metro in metro_areas:
+        print('{:18} {:2} {:6.0f} {:4.0f} {:6.0f}'.format(*metro))
+
+def list_instances(metro_areas):
+    metro_areas = [MetroArea(*fields) for fields in metro_areas]
+    for metro in metro_areas:
+        print(metro)
+
+
+if __name__ == '__main__':
+    #list(load())
+    list_instances(load())
+
+