StarMirror/data-science-ipython-notebooks
1
0
Fork 0
mirror of https://github.com/donnemartin/data-science-ipython-notebooks.git synced 2024-03-22 13:30:56 +08:00
Code Issues Projects Releases Wiki Activity

Updated markdown discussions for clarity and consistency.

Browse Source
This commit is contained in:
Donne Martin 2015-01-27 10:25:08 -05:00
parent 03597adc58
commit 3574594172
1 changed files with 43 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
core/structs_utils.ipynb
View File

@ -1,7 +1,7 @@
{
"metadata": {
"name": "",
"signature": "sha256:893799227c6632abab6f36b3299512e1f724d3a9e69a9cc0b81a3ff9c872f370"
"signature": "sha256:fed6792b1275b1a5b92e846b93e797942c4eac23ccf1c44b750b469e3f33ffbe"
},
"nbformat": 3,
"nbformat_minor": 0,
@ -37,6 +37,13 @@
"## slice"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"Slice selects a section of list types (arrays, tuples, NumPy arrays) with its arguments [start:end]: start is included, end is not. The number of elements in the result is stop - end."
]
},
{
"cell_type": "markdown",
"metadata": {},
@ -48,7 +55,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Select a section of list types (arrays, tuples, NumPy arrays) using [start:stop]. start is included, stop is not. The number of elements in the result is stop - start."
"Slice 4 elements starting at index 6 and ending at index 9:"
]
},
{
@ -76,7 +83,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Omit start to default to start of the sequence"
"Omit start to default to start of the sequence:"
]
},
{
@ -103,7 +110,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Omit end to default to end of the sequence"
"Omit end to default to end of the sequence:"
]
},
{
@ -130,7 +137,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Negative indices slice relative to the end"
"Negative indices slice relative to the end:"
]
},
{
@ -157,7 +164,9 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Slice can also take a step such as the one below, which takes every other element"
"Slice can also take a step [start:end:step].\n",
"\n",
"Get every other element:"
]
},
{
@ -211,7 +220,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Assign elements to a slice. Slice range does not have to equal number of elements to assign."
"You can assign elements to a slice (note the slice range does not have to equal number of elements to assign):"
]
},
{
@ -240,7 +249,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Compare assigning into a slice (above) versus assigning into an index (below)"
"Compare the output of assigning into a slice (above) versus the output of assigning into an index (below):"
]
},
{
@ -276,7 +285,9 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Generate a list of evenly spaced integers. Note: range is no longer avalable in Python 3 "
"Generate a list of evenly spaced integers with range or xrange. Note: range in Python 3 returns a generator and xrange is not available.\n",
"\n",
"Generate 10 integers:"
]
},
{
@ -303,7 +314,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Range can take start, stop, and step arguments"
"Range can take start, stop, and step arguments:"
]
},
{
@ -330,7 +341,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"It is very common to iterate through sequences by index with range"
"It is very common to iterate through sequences by index with range:"
]
},
{
@ -361,7 +372,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"xrange is recommended for longer ranges and is available in Python 3 as range. It returns an iterator that generates integers one by one rather than all at once and storing them in a large list."
"For longer ranges, xrange is recommended and is available in Python 3 as range. It returns an iterator that generates integers one by one rather than all at once and storing them in a large list."
]
},
{
@ -416,7 +427,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Find the location where an element should be inserted to keep the list sorted"
"Find the location where an element should be inserted to keep the list sorted:"
]
},
{
@ -444,7 +455,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Inserts an element into a location to keep the list sorted"
"Insert an element into a location to keep the list sorted:"
]
},
{
@ -508,7 +519,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Sort by secondary key: str length"
"Sort by the secondary key of str length:"
]
},
{
@ -544,7 +555,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Return a new sorted list from the elements of a sequence"
"Return a new sorted list from the elements of a sequence O(n log n):"
]
},
{
@ -591,7 +602,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"It's common to get a sorted list of unique elements by combining sorted and set"
"It's common to get a sorted list of unique elements by combining sorted and set:"
]
},
{
@ -626,7 +637,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Iterates over the sequence elements in reverse order"
"Iterate over the sequence elements in reverse order:"
]
},
{
@ -660,7 +671,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"enumerate gives you the index of a collection and the value"
"Get the index of a collection and the value:"
]
},
{
@ -697,7 +708,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Pairs up the elements of sequences to create a list of tuples"
"Pair up the elements of sequences to create a list of tuples:"
]
},
{
@ -726,7 +737,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Takes an arbitrary number of sequences. The number of elements it produces is determined by the shortest sequence."
"Zip takes an arbitrary number of sequences. The number of elements it produces is determined by the shortest sequence:"
]
},
{
@ -754,7 +765,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"It is common to use zip for simultaneously iterating over multiple sequences combined with enumerate"
"It is common to use zip for simultaneously iterating over multiple sequences combined with enumerate:"
]
},
{
@ -783,7 +794,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"zip can unzip a zipped sequence, which you can think of as converting a list of rows into a list of columns"
"Zip can unzip a zipped sequence, which you can think of as converting a list of rows into a list of columns:"
]
},
{
@ -839,7 +850,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Concisely form a new list by filtering the elements of a sequence and transforming the elements passing the filter. List comprehensions take the form:\n",
"List comprehensions concisely form a new list by filtering the elements of a sequence and transforming the elements passing the filter. List comprehensions take the form:\n",
"```python\n",
"[expr for val in collection if condition]\n",
"```\n",
@ -856,7 +867,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Convert to upper case all strings that start with a 'b'"
"Convert to upper case all strings that start with a 'b':"
]
},
{
@ -884,7 +895,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"List comprehensions can be nested"
"List comprehensions can be nested:"
]
},
{
@ -919,7 +930,9 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Create a lookup map of strings and their locations in the list for strings that start with a 'b'"
"A dict comprehension is similar to a list comprehension but returns a dict.\n",
"\n",
"Create a mapping of strings and their locations in the list for strings that start with a 'b':"
]
},
{
@ -953,7 +966,9 @@
"cell_type": "markdown",
"metadata": {},
"source": [
"Get the unique lengths of strings that start with a 'b'"
"A set comprehension is similar to a list comprehension but returns a set.\n",
"\n",
"Get the unique lengths of strings that start with a 'b':"
]
},
{