forked from bslatkin/effectivepython
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathitem_006.py
More file actions
executable file
·151 lines (111 loc) · 3.05 KB
/
item_006.py
File metadata and controls
executable file
·151 lines (111 loc) · 3.05 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
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
#!/usr/bin/env PYTHONHASHSEED=1234 python3
# Copyright 2014-2024 Brett Slatkin, Pearson Education Inc.
#
# 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.
### Start book environment setup
import random
random.seed(1234)
import logging
from pprint import pprint
from sys import stdout as STDOUT
# Write all output to a temporary directory
import atexit
import gc
import io
import os
import tempfile
TEST_DIR = tempfile.TemporaryDirectory()
atexit.register(TEST_DIR.cleanup)
# Make sure Windows processes exit cleanly
OLD_CWD = os.getcwd()
atexit.register(lambda: os.chdir(OLD_CWD))
os.chdir(TEST_DIR.name)
def close_open_files():
everything = gc.get_objects()
for obj in everything:
if isinstance(obj, io.IOBase):
obj.close()
atexit.register(close_open_files)
### End book environment setup
print("Example 1")
first = (1, 2, 3)
print("Example 2")
second = (1, 2, 3,)
second_wrapped = (
1,
2,
3, # Optional comma
)
print("Example 3")
third = 1, 2, 3
print("Example 4")
fourth = 1, 2, 3,
print("Example 5")
assert first == second == third == fourth
print("Example 6")
empty = ()
print("Example 7")
single_with = (1,)
single_without = (1)
assert single_with != single_without
assert single_with[0] == single_without
print("Example 8")
single_parens = (1,)
single_no_parens = 1,
assert single_parens == single_no_parens
print("Example 9")
def calculate_refund(a, b, c):
return 123_000_000
def get_order_value(a, b):
pass
def get_tax(a, b):
pass
def adjust_discount(a):
return 1
import types
user = types.SimpleNamespace(address='Fake address')
order = types.SimpleNamespace(
id='my order',
dest='my destination')
to_refund = calculate_refund(
get_order_value(user, order.id),
get_tax(user.address, order.dest),
adjust_discount(user) + 0.1),
print("Example 10")
print(type(to_refund))
print("Example 11")
to_refund2 = calculate_refund(
get_order_value(user, order.id),
get_tax(user.address, order.dest),
adjust_discount(user) + 0.1,
) # No trailing comma
print(type(to_refund2))
print("Example 12")
value_a = 1, # No parentheses, right
list_b = [1,] # No parentheses, wrong
list_c = [(1,)] # Parentheses, right
print('A:', value_a)
print('B:', list_b)
print('C:', list_c)
print("Example 13")
def get_coupon_codes(user):
return [['DEAL20']]
(a1,), = get_coupon_codes(user)
(a2,) = get_coupon_codes(user)
(a3), = get_coupon_codes(user)
(a4) = get_coupon_codes(user)
a5, = get_coupon_codes(user)
a6 = get_coupon_codes(user)
assert a1 not in (a2, a3, a4, a5, a6)
assert a2 == a3 == a5
assert a4 == a6