Commit f5f789c9 authored by Thomas Etherington's avatar Thomas Etherington Committed by Maxim Belkin
Browse files

01-numpy.md: update the library import callout (#689)

parent 60835490
...@@ -218,19 +218,7 @@ Importing a library is like getting a piece of lab equipment out of a storage lo ...@@ -218,19 +218,7 @@ Importing a library is like getting a piece of lab equipment out of a storage lo
up on the bench. Libraries provide additional functionality to the basic Python package, much like up on the bench. Libraries provide additional functionality to the basic Python package, much like
a new piece of equipment adds functionality to a lab space. Just like in the lab, importing too a new piece of equipment adds functionality to a lab space. Just like in the lab, importing too
many libraries can sometimes complicate and slow down your programs - so we only import what we many libraries can sometimes complicate and slow down your programs - so we only import what we
need for each program. need for each program.
> ## Scientists Dislike Typing
>
> We will always use the syntax `import numpy` to import NumPy.
> However, in order to save typing, it is
> [often suggested](http://www.scipy.org/getting-started.html#an-example-script)
> to make a shortcut like so: `import numpy as np`.
> If you ever see Python code online using a NumPy function with `np`
> (for example, `np.loadtxt(...)`), it's because they've used this shortcut.
> When working with other people, it is important to agree on a convention of how common libraries
> are imported.
{: .callout}
Once we've imported the library, we can ask the library to read our data file for us: Once we've imported the library, we can ask the library to read our data file for us:
...@@ -276,6 +264,18 @@ To save space, ...@@ -276,6 +264,18 @@ To save space,
Python displays numbers as `1.` instead of `1.0` Python displays numbers as `1.` instead of `1.0`
when there's nothing interesting after the decimal point. when there's nothing interesting after the decimal point.
> ## Importing libraries with shortcuts
>
> In this lesson we use the `import numpy` [syntax]({{ page.root }}/reference/#syntax) to import NumPy.
> However, shortcuts such as `import numpy as np` are frequently used. Importing NumPy this way means that after the
> inital import, rather than writing `numpy.loadtxt(...)`, you can now write `np.loadtxt(...)`. Some
> people prefer this as it is quicker to type and results in shorter lines of code - especially for libraries
> with long names! You will frequently see Python code online using a NumPy function with `np`, and it's
> because they've used this shortcut. It makes no difference which approach you choose to take, but you must be
> consistent as if you use `import numpy as np` then `numpy.loadtxt(...)` will not work, and you must use `np.loadtxt(...)`
> instead. Because of this, when working with other people it is important you agree on how libraries are imported.
{: .callout}
Our call to `numpy.loadtxt` read our file Our call to `numpy.loadtxt` read our file
but didn't save the data in memory. but didn't save the data in memory.
To do that, To do that,
......
...@@ -240,6 +240,9 @@ string ...@@ -240,6 +240,9 @@ string
: Short for "character string", : Short for "character string",
a [sequence](#sequence) of zero or more characters. a [sequence](#sequence) of zero or more characters.
syntax
: The rules that define how code must be written for a computer to understand.
syntax error syntax error
: A programming error that occurs when statements are in an order or contain characters : A programming error that occurs when statements are in an order or contain characters
not expected by the programming language. not expected by the programming language.
......
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