effectivepython/example_code/item_22.py at master · AISTLAB/effectivepython · GitHub

History

executable file

201 lines (157 loc) · 5.35 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

#!/usr/bin/env python3

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

# http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

# Preamble to mimick book environment

import logging

from pprint import pprint

from sys import stdout as STDOUT

# Example 1

class SimpleGradebook(object):

def __init__(self):

self._grades = {}

def add_student(self, name):

self._grades[name] = []

def report_grade(self, name, score):

self._grades[name].append(score)

def average_grade(self, name):

grades = self._grades[name]

return sum(grades) / len(grades)

# Example 2

book = SimpleGradebook()

book.add_student('Isaac Newton')

book.report_grade('Isaac Newton', 90)

book.report_grade('Isaac Newton', 95)

book.report_grade('Isaac Newton', 85)

print(book.average_grade('Isaac Newton'))

# Example 3

class BySubjectGradebook(object):

def __init__(self):

self._grades = {}

def add_student(self, name):

self._grades[name] = {}

# Example 4

def report_grade(self, name, subject, grade):

by_subject = self._grades[name]

grade_list = by_subject.setdefault(subject, [])

grade_list.append(grade)

def average_grade(self, name):

by_subject = self._grades[name]

total, count = 0, 0

for grades in by_subject.values():

total += sum(grades)

count += len(grades)

return total / count

# Example 5

book = BySubjectGradebook()

book.add_student('Albert Einstein')

book.report_grade('Albert Einstein', 'Math', 75)

book.report_grade('Albert Einstein', 'Math', 65)

book.report_grade('Albert Einstein', 'Gym', 90)

book.report_grade('Albert Einstein', 'Gym', 95)

print(book.average_grade('Albert Einstein'))

# Example 6

class WeightedGradebook(object):

def __init__(self):

self._grades = {}

def add_student(self, name):

self._grades[name] = {}

def report_grade(self, name, subject, score, weight):

by_subject = self._grades[name]

grade_list = by_subject.setdefault(subject, [])

grade_list.append((score, weight))

# Example 7

def average_grade(self, name):

by_subject = self._grades[name]

score_sum, score_count = 0, 0

for subject, scores in by_subject.items():

subject_avg, total_weight = 0, 0

for score, weight in scores:

subject_avg += score * weight

total_weight += weight

score_sum += subject_avg / total_weight

score_count += 1

return score_sum / score_count

# Example 8

book = WeightedGradebook()

book.add_student('Albert Einstein')

book.report_grade('Albert Einstein', 'Math', 80, 0.10)

book.report_grade('Albert Einstein', 'Math', 70, 0.80)

book.report_grade('Albert Einstein', 'Gym', 100, 0.40)

book.report_grade('Albert Einstein', 'Gym', 85, 0.60)

print(book.average_grade('Albert Einstein'))

# Example 9

grades = []

grades.append((95, 0.45))

grades.append((85, 0.55))

total = sum(score * weight for score, weight in grades)

total_weight = sum(weight for _, weight in grades)

average_grade = total / total_weight

print(average_grade)

# Example 10

grades = []

grades.append((95, 0.45, 'Great job'))

grades.append((85, 0.55, 'Better next time'))

total = sum(score * weight for score, weight, _ in grades)

total_weight = sum(weight for _, weight, _ in grades)

average_grade = total / total_weight

print(average_grade)

# Example 11

import collections

Grade = collections.namedtuple('Grade', ('score', 'weight'))

# Example 12

class Subject(object):

def __init__(self):

self._grades = []

def report_grade(self, score, weight):

self._grades.append(Grade(score, weight))

def average_grade(self):

total, total_weight = 0, 0

for grade in self._grades:

total += grade.score * grade.weight

total_weight += grade.weight

return total / total_weight

# Example 13

class Student(object):

def __init__(self):

self._subjects = {}

def subject(self, name):

if name not in self._subjects:

self._subjects[name] = Subject()

return self._subjects[name]

def average_grade(self):

total, count = 0, 0

for subject in self._subjects.values():

total += subject.average_grade()

count += 1

return total / count

# Example 14

class Gradebook(object):

def __init__(self):

self._students = {}

def student(self, name):

if name not in self._students:

self._students[name] = Student()

return self._students[name]

# Example 15

book = Gradebook()

albert = book.student('Albert Einstein')

math = albert.subject('Math')

math.report_grade(80, 0.10)

math.report_grade(70, 0.80)

gym = albert.subject('Gym')

gym.report_grade(100, 0.40)

gym.report_grade(85, 0.60)

print(albert.average_grade())

effectivepython/example_code/item_22.py at master · AISTLAB/effectivepython · GitHub

Expand file tree

Breadcrumbs

item_22.py

Latest commit

History

Breadcrumbs

item_22.py

File metadata and controls