Session 4 homework

Students/Tyler G/session4/dictionaries_sets_lab.py

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+sample_dict = {"name": "Chris", "city": "Seattle", "cake": "Chocolate"}
+
+del sample_dict['cake']
+
+print sample_dict
+
+sample_dict['fruit'] = "Mango"
+
+print sample_dict
+
+print sample_dict.keys()
+print sample_dict.values()
+
+print 'cake' in sample_dict.keys()
+print 'Mango' in sample_dict.values()
+
+nums = list(range(0,15))
+hexidecimal = [0,1,2,3,4,5,6,7,8,9,"A","B","C","D","E","F"]
+
+print dict(zip(nums, hexidecimal))
+
+for key in sample_dict.keys():
+	value = sample_dict[key].count('t')
+	sample_dict[key] = value
+
+s2 = set([i for i in range(1,21) if i % 2 == 0])
+s3 = set([i for i in range(1,21) if i % 3 == 0])
+s4 = set([i for i in range(1,21) if i % 4 == 0])
+
+print s3.issubset(s2)
+print s4.issubset(s2)
+
+python_set = set("Python")
+python_set.add("i")
+
+marathon_set = frozenset("marathon")
+python_set.union(marathon_set)
+python_set.intersection(marathon_set)

Students/Tyler G/session4/exceptions_lab.py

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+def safe_input():
+    try:
+        input = raw_input("Try to escape this: ")
+    except EOFError:
+        print "That won't work"
+        return None
+    except KeyboardInterrupt:
+        print "You used Ctrl-C or Ctrl-D."
+        return None
+    else:
+        print "Okay that works"
+        return input
+
+
+
+
+if __name__ == "__main__":  
+    safe_input()

Students/Tyler G/session4/files_lab.py

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+import os
+from collections import Counter
+
+print "The current working directory is: ", os.getcwd()
+print "\n"
+
+path = 'C:\mystuff\pythonclass\introtopython\examples\session01'
+os.chdir(path)
+
+print "Now the current working directory is: ", os.getcwd()
+print "\n"
+print "The files in this directory are: ", os.listdir(path)
+print "\n"
+
+file = open("students.txt", "r")
+lines = file.readlines()
+
+languages = []
+
+for line in lines[1:]:
+    for item in line[line.index(':') + 1:].split(', '):
+        languages.append(item.strip())
+
+for index, value in enumerate(languages):
+    if value == '':
+        languages.pop(index)
+
+hash_languages = Counter(languages)
+
+for key, value in hash_languages.iteritems():
+    if key == '':
+        pass
+    else:
+        print "%d student(s) know the '%s' language" % (value, key)
+
+file.close()

Students/Tyler G/session4/sieve of eratosthenes.py

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+def sieve_eratosthenes(n):
+    """
+    Generate a list of odd integers from 3 to "n".
+    Use the first element in the list to iterate over the
+    remaining elements to remove it's multiples. Rinse and repeat.
+    """
+    numbers = range(3, n + 1, 2)
+    for index, value in enumerate(numbers):
+        for num in numbers[index + 2:]:
+            if num % value == 0:
+                numbers.remove(num)
+    numbers.append(2)
+    return sorted(numbers)
+
+if __name__ == "__main__":
+    print sieve_eratosthenes(50)
+
+