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output fix for for-loop leak

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This commit is contained in:
rasbt 2014-05-02 16:14:09 -04:00
parent 3c42a45c60
commit cb5853e6da
4 changed files with 85 additions and 5 deletions
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57
.ipynb_checkpoints/not_so_obvious_python_stuff-checkpoint.ipynb
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@ -1,7 +1,7 @@
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@ -2577,6 +2577,52 @@
"metadata": {},
"outputs": []
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"#### In Python 3.x for-loop variables don't leak into the global namespace anymore"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"This goes back to a change that was made in Python 3.x and is described in [What\u2019s New In Python 3.0](https://docs.python.org/3/whatsnew/3.0.html) as follows:\n",
"\n",
"\"List comprehensions no longer support the syntactic form `[... for var in item1, item2, ...]`. Use `[... for var in (item1, item2, ...)]` instead. Also note that list comprehensions have different semantics: they are closer to syntactic sugar for a generator expression inside a `list()` constructor, and in particular the loop control variables are no longer leaked into the surrounding scope.\""
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"i = 1\n",
"print([i for i in range(5)])\n",
"print(i, '-> i in global')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"[0, 1, 2, 3, 4]\n",
"1 -> i in global\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"In Python 2.x this would print \n",
"`4 -> i in global`"
]
},
{
"cell_type": "markdown",
"metadata": {},
@ -3345,6 +3391,7 @@
"metadata": {},
"source": [
"#### 05/02/2014\n",
"- new section in Python 3.x and Python 2.x key differences: for-loop leak<\n",
"- new section: Metaclasses - What creates a new instance of a class? \n",
"\n",
"#### 05/01/2014\n",
@ -3354,6 +3401,14 @@
"- minor fixes of typos \n",
"- new section: \"Only the first clause of generators is evaluated immediately\""
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}

10
.ipynb_checkpoints/scope_resolution_legb_rule-checkpoint.ipynb
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@ -1,7 +1,7 @@
{
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"signature": "sha256:1e3a847a38ee33d41e745f74fe6b8a143b9aeb47d0a1e3029ea52899d97687cb"
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"nbformat_minor": 0,
@ -1076,6 +1076,14 @@
"\n",
"\"List comprehensions no longer support the syntactic form `[... for var in item1, item2, ...]`. Use `[... for var in (item1, item2, ...)]` instead. Also note that list comprehensions have different semantics: they are closer to syntactic sugar for a generator expression inside a `list()` constructor, and in particular the loop control variables are no longer leaked into the surrounding scope.\""
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}

13
not_so_obvious_python_stuff.ipynb
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@ -1,7 +1,7 @@
{
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"nbformat": 3,
"nbformat_minor": 0,
@ -2620,7 +2620,7 @@
"metadata": {},
"source": [
"In Python 2.x this would print \n",
"`print(4, '-> i in global')`"
"`4 -> i in global`"
]
},
{
@ -3391,6 +3391,7 @@
"metadata": {},
"source": [
"#### 05/02/2014\n",
"- new section in Python 3.x and Python 2.x key differences: for-loop leak<\n",
"- new section: Metaclasses - What creates a new instance of a class? \n",
"\n",
"#### 05/01/2014\n",
@ -3400,6 +3401,14 @@
"- minor fixes of typos \n",
"- new section: \"Only the first clause of generators is evaluated immediately\""
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}

10
tutorials/scope_resolution_legb_rule.ipynb
View File

@ -1,7 +1,7 @@
{
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},
"nbformat": 3,
"nbformat_minor": 0,
@ -1076,6 +1076,14 @@
"\n",
"\"List comprehensions no longer support the syntactic form `[... for var in item1, item2, ...]`. Use `[... for var in (item1, item2, ...)]` instead. Also note that list comprehensions have different semantics: they are closer to syntactic sugar for a generator expression inside a `list()` constructor, and in particular the loop control variables are no longer leaked into the surrounding scope.\""
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}