It is almost sure that you will want to open manual pages for library functions. You can do it with the help of the help
command.
In [1]: import numpy
In [2]: help(numpy.ar
numpy.arange numpy.arcsinh numpy.argmax numpy.argwhere
numpy.arccos numpy.arctan numpy.argmin numpy.around
numpy.arccosh numpy.arctan2 numpy.argpartition numpy.array >
numpy.arcsin numpy.arctanh numpy.argsort numpy.array2string
You just type part of the function then press Tab
key to get a list of function.
You select the function you wish using the arrow keys then press Enter
. Then you close the function call with a )
and press Enter
.
Help on ufunc object:
arcsin = class ufunc(builtins.object)
 Functions that operate element by element on whole arrays.

 To see the documentation for a specific ufunc, use `info`. For
 example, ``np.info(np.sin)``. Because ufuncs are written in C
 (for speed) and linked into Python with NumPy's ufunc facility,
 Python's help() function finds this page whenever help() is called
 on a ufunc.

 A detailed explanation of ufuncs can be found in the docs for :ref:`ufuncs`.

 Calling ufuncs:
 ===============

 op(*x[, out], where=True, **kwargs)
 Apply `op` to the arguments `*x` elementwise, broadcasting the arguments.

 The broadcasting rules are:

 * Dimensions of length 1 may be prepended to either array.
 * Arrays may be repeated along dimensions of length 1.
:
You can exist the help screen using Shift+Q
.
Another way of achieving the same result is to append a question mark at the end of the function then press Enter
(will give you information from docstrings).
In [3]: numpy.arcsin?
The result is something like shown below:
Call signature: numpy.arcsin(*args, **kwargs)
Type: ufunc
String form:
File: ~/env/data_analysis/lib/python3.5/sitepackages/numpy/__init__.py
Docstring:
arcsin(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj])
Inverse sine, elementwise.
Parameters

x : array_like
`y`coordinate on the unit circle.
out : ndarray, None, or tuple of ndarray and None, optional
A location into which the result is stored. If provided, it must have
a shape that the inputs broadcast to. If not provided or `None`,
a freshlyallocated array is returned. A tuple (possible only as a
keyword argument) must have length equal to the number of outputs.
where : array_like, optional
Values of True indicate to calculate the ufunc at that position, values
of False indicate to leave the value in the output alone.
:
Note:
In order to use Tab completion you have to have readline
installed. You can install it using pip
by running the following command in the terminal.
pip install readline