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Added slice snippets

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Donne Martin 2015-01-25 09:04:56 -05:00
parent ff31684ee5
commit 60b1901186
1 changed files with 201 additions and 10 deletions
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211
core/structs.ipynb
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@ -1,7 +1,7 @@
{
"metadata": {
"name": "",
"signature": "sha256:d7e86a84d9ac272fcd99e1aadbc8c73b80d1affd3c0533649f6842229dee5f2b"
"signature": "sha256:f24f6112f8e8e28d262a4f84be84d1ae459154a9a445687d55392ff177e6a03c"
},
"nbformat": 3,
"nbformat_minor": 0,
@ -574,8 +574,8 @@
"\n",
"# Find the location where an element should be inserted to keep the\n",
"# list sorted\n",
"c_list = [1, 2, 2, 4, 8, 10]\n",
"bisect.bisect(c_list, 5)"
"c_list = [1, 2, 2, 3, 5, 13]\n",
"bisect.bisect(c_list, 8)"
],
"language": "python",
"metadata": {},
@ -583,20 +583,20 @@
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 40,
"prompt_number": 25,
"text": [
"4"
"5"
]
}
],
"prompt_number": 40
"prompt_number": 25
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Inserts an element into a location to keep the list sorted\n",
"bisect.insort(c_list, 5)\n",
"bisect.insort(c_list, 8)\n",
"c_list"
],
"language": "python",
@ -605,13 +605,204 @@
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 41,
"prompt_number": 26,
"text": [
"[1, 2, 2, 4, 5, 8, 10]"
"[1, 2, 2, 3, 5, 8, 13]"
]
}
],
"prompt_number": 41
"prompt_number": 26
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## slice"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"![alt text](http://www.nltk.org/images/string-slicing.png)"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Select a section of list types (arrays, tuples, NumPy arrays)\n",
"# start:stop\n",
"# start is included, stop is not\n",
"# number of elements in the result is stop - start\n",
"d_list = 'Monty Python'\n",
"d_list[6:10]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 27,
"text": [
"'Pyth'"
]
}
],
"prompt_number": 27
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Omit start to default to start of the sequence\n",
"d_list[:5]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 28,
"text": [
"'Monty'"
]
}
],
"prompt_number": 28
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Omit end to default to end of the sequence\n",
"d_list[6:]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 29,
"text": [
"'Python'"
]
}
],
"prompt_number": 29
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Negative indices slice relative to the end\n",
"d_list[-12:-7]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 30,
"text": [
"'Monty'"
]
}
],
"prompt_number": 30
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Slice can also take a step such as the one below, which takes\n",
"# every other element\n",
"e_list[::2]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 33,
"text": [
"[1, 2, 5, 13]"
]
}
],
"prompt_number": 33
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Passing -1 for the step reverses the list or tuple:\n",
"e_list[::-1]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 34,
"text": [
"[13, ['H', 'a', 'l', 'l'], 5, 3, 2, 1, 1]"
]
}
],
"prompt_number": 34
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Assign elements to a slice\n",
"# Slice range does not have to equal number of elements to assign\n",
"e_list = [1, 1, 2, 3, 5, 8, 13]\n",
"e_list[5:] = ['H', 'a', 'l', 'l']\n",
"e_list"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 31,
"text": [
"[1, 1, 2, 3, 5, 'H', 'a', 'l', 'l']"
]
}
],
"prompt_number": 31
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# Compare assigning into a slice (above) versus assigning into\n",
"# an inde\n",
"e_list"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 32,
"text": [
"[1, 1, 2, 3, 5, ['H', 'a', 'l', 'l'], 13]"
]
}
],
"prompt_number": 32
},
{
"cell_type": "code",