使用Jupyter Notebook 學習 Python
- coldplay.xixi轉載
- 2020-09-28 16:26:342954瀏覽
有了 Jupyter、PyHamcrest，用一點測試的程式碼把它們連在一起，你就可以教任何適用於單元測試的 Python 內容。
Python影片教學專欄為大家詳細介紹~
import unittest
def run_test(klass):
suite = unittest.TestLoader().loadTestsFromTestCase(klass)
unittest.TextTestRunner(verbosity=2).run(suite)
return klass复制代码現在，裝備已經就緒，可以進行第一次練習了。 在教學中，從一個簡單的練習開始，建立信心總是一個好主意。 那麼，讓我們來修復一個非常簡單的測驗：@run_test
class TestNumbers(unittest.TestCase):
def test_equality(self):
expected_value = 3 # 只改这一行
self.assertEqual(1+1, expected_value)复制代码 test_equality (__main__.TestNumbers) ... FAIL
======================================================================
FAIL: test_equality (__main__.TestNumbers)
----------------------------------------------------------------------
Traceback (most recent call last):
File "<ipython-input-7-5ebe25bc00f3>", line 6, in test_equality
self.assertEqual(1+1, expected_value)
AssertionError: 2 != 3
----------------------------------------------------------------------
Ran 1 test in 0.002s
FAILED (failures=1)复制代码「只改變這一行」 對學生來說是一個有用的標記。它準確地表明了需要修改的內容。否則，學生可以透過將第一行改為 return 來修復測驗。
@run_test
class TestNumbers(unittest.TestCase):
def test_equality(self):
expected_value = 2 # 修复后的代码行
self.assertEqual(1+1, expected_value)复制代码 test_equality (__main__.TestNumbers) ... ok
----------------------------------------------------------------------
Ran 1 test in 0.002s
OK复制代码然而，很快，unittest 庫的原生斷言將被證明是不夠的。在 pytest 中，透過重寫 assert 中的字節碼來解決這個問題，使其具有神奇的屬性和各種啟發式方法。但這在 Jupyter notebook 中就不容易實現了。是時候挖出一個好的斷言庫了：PyHamcrest。
from hamcrest import *
@run_test
class TestList(unittest.TestCase):
def test_equality(self):
things = [1,
5, # 只改这一行
3]
assert_that(things, has_items(1, 2, 3))复制代码 test_equality (__main__.TestList) ... FAIL
======================================================================
FAIL: test_equality (__main__.TestList)
----------------------------------------------------------------------
Traceback (most recent call last):
File "<ipython-input-11-96c91225ee7d>", line 8, in test_equality
assert_that(things, has_items(1, 2, 3))
AssertionError:
Expected: (a sequence containing <1> and a sequence containing <2> and a sequence containing <3>)
but: a sequence containing <2> was <[1, 5, 3]>
----------------------------------------------------------------------
Ran 1 test in 0.004s
FAILED (failures=1)复制代码PyHamcrest 不僅擅長靈活的斷言，它還擅長清晰的錯誤訊息。正因為如此，問題就顯而易見了。 [1, 5, 3] 不包含2，而且看起來很醜：
@run_test
class TestList(unittest.TestCase):
def test_equality(self):
things = [1,
2, # 改完的行
3]
assert_that(things, has_items(1, 2, 3))复制代码 test_equality (__main__.TestList) ... ok
----------------------------------------------------------------------
Ran 1 test in 0.001s
OK复制代码使用Jupyter、PyHamcrest 和一點測試的黏合程式碼，你可以教授任何適用於單元測試的Python 主題。 例如，下面可以幫助展示 Python 從字串中去掉空白的不同方法之間的差異。 source_string = " hello world "
@run_test
class TestList(unittest.TestCase):
# 这是个赠品：它可以工作！
def test_complete_strip(self):
result = source_string.strip()
assert_that(result,
all_of(starts_with("hello"), ends_with("world")))
def test_start_strip(self):
result = source_string # 只改这一行
assert_that(result,
all_of(starts_with("hello"), ends_with("world ")))
def test_end_strip(self):
result = source_string # 只改这一行
assert_that(result,
all_of(starts_with(" hello"), ends_with("world")))复制代码 test_complete_strip (__main__.TestList) ... ok
test_end_strip (__main__.TestList) ... FAIL
test_start_strip (__main__.TestList) ... FAIL
======================================================================
FAIL: test_end_strip (__main__.TestList)
----------------------------------------------------------------------
Traceback (most recent call last):
File "<ipython-input-16-3db7465bd5bf>", line 19, in test_end_strip
assert_that(result,
AssertionError:
Expected: (a string starting with ' hello' and a string ending with 'world')
but: a string ending with 'world' was ' hello world '
======================================================================
FAIL: test_start_strip (__main__.TestList)
----------------------------------------------------------------------
Traceback (most recent call last):
File "<ipython-input-16-3db7465bd5bf>", line 14, in test_start_strip
assert_that(result,
AssertionError:
Expected: (a string starting with 'hello' and a string ending with 'world ')
but: a string starting with 'hello' was ' hello world '
----------------------------------------------------------------------
Ran 3 tests in 0.006s
FAILED (failures=2)复制代码理想情況下，學生會意識到 .lstrip() 和 .rstrip() 這兩個方法可以滿足他們的需要。但如果他們不這樣做，而是試圖到處使用.strip() 的話：
source_string = " hello world "
@run_test
class TestList(unittest.TestCase):
# 这是个赠品：它可以工作！
def test_complete_strip(self):
result = source_string.strip()
assert_that(result,
all_of(starts_with("hello"), ends_with("world")))
def test_start_strip(self):
result = source_string.strip() # 改完的行
assert_that(result,
all_of(starts_with("hello"), ends_with("world ")))
def test_end_strip(self):
result = source_string.strip() # 改完的行
assert_that(result,
all_of(starts_with(" hello"), ends_with("world")))复制代码 test_complete_strip (__main__.TestList) ... ok
test_end_strip (__main__.TestList) ... FAIL
test_start_strip (__main__.TestList) ... FAIL
======================================================================
FAIL: test_end_strip (__main__.TestList)
----------------------------------------------------------------------
Traceback (most recent call last):
File "<ipython-input-17-6f9cfa1a997f>", line 19, in test_end_strip
assert_that(result,
AssertionError:
Expected: (a string starting with ' hello' and a string ending with 'world')
but: a string starting with ' hello' was 'hello world'
======================================================================
FAIL: test_start_strip (__main__.TestList)
----------------------------------------------------------------------
Traceback (most recent call last):
File "<ipython-input-17-6f9cfa1a997f>", line 14, in test_start_strip
assert_that(result,
AssertionError:
Expected: (a string starting with 'hello' and a string ending with 'world ')
but: a string ending with 'world ' was 'hello world'
----------------------------------------------------------------------
Ran 3 tests in 0.007s
FAILED (failures=2)复制代码他們會得到一個不同的錯誤訊息，顯示去除了過多的空白：source_string = " hello world "
@run_test
class TestList(unittest.TestCase):
# 这是个赠品：它可以工作！
def test_complete_strip(self):
result = source_string.strip()
assert_that(result,
all_of(starts_with("hello"), ends_with("world")))
def test_start_strip(self):
result = source_string.lstrip() # Fixed this line
assert_that(result,
all_of(starts_with("hello"), ends_with("world ")))
def test_end_strip(self):
result = source_string.rstrip() # Fixed this line
assert_that(result,
all_of(starts_with(" hello"), ends_with("world")))复制代码 test_complete_strip (__main__.TestList) ... ok
test_end_strip (__main__.TestList) ... ok
test_start_strip (__main__.TestList) ... ok
----------------------------------------------------------------------
Ran 3 tests in 0.005s
OK复制代码在一個比較真實的教程中，會有更多的例子和更多的解釋。這種使用 Jupyter Notebook 的技巧，有的例子可以用，有的例子需要修正，可以用於實時教學，可以用於視頻課，甚至，可以用更多的其它零散用途，讓學生自己完成一個教程。 現在就去分享你的知識吧!
更多相關免費學習推薦：python影片教學
以上是使用Jupyter Notebook 學習 Python的詳細內容。更多資訊請關注PHP中文網其他相關文章！
陳述：
本文轉載於：juejin.im。如有侵權，請聯絡admin@php.cn刪除