flags are preceded by one or two hyphens (e.g., -flag or --flag)
a command can have zero or more arguments
commands
variables are names for values
in python the "=" symbol assigns the value on the right to the name on the left, e.g., my_variable = "my variable's value"
the variable is created when a value is assigned to it
variable names
can only contain letters, digits, and underscores
cannot start with a digit
should be descriptive
variables
int: an integer, e.g., 52 or -52
string: a set of characters; specified within single or double quotes, e.g., 'i am a string' or "my_string"
float: a floating-point number; specified with a decimal point, e.g., 52.001 or -52.001
... plus more we'll get to later
data types
functions (also called methods) are predefined actions
like variables, each function has a name
unlike variables, functions can take arguments (also called parameters)
you can call a function by invoking it by name and passing it zero or more arguments in parentheses, e.g., len('my_string')
functions
python libraries are self-contained groups of python modules that provide additional functionality to the main python language.
many libraries are open source, meaning you can freely use, look at, and repurpose them.
our anacondaenvironment will help us import python libraries into our python programs, allowing us to use the libraries' classes, functions, and variables in our notebooks transparently
libraries
tabular data is information in table form
proprietary programs like excel and numbers create table-like data, but they frequently include styling and extra metadata that can confuse and bog down programs
it is best to use open, plaintext formats for your data, including tabular data.
the best examples are CSV and TSV files, which stand for Comma-Separated Value and Tab-Separated Value, respectively.
tabular data
use DataFrame.iloc() to select data by index position
use DataFrame.loc() to select data by (column/row) label
when in doubt, use help(data.loc) and help(data.iloc) to check