Python Certified Entry-Level Programmer (PCEP-30-XX) Study Cards

A lexis, or dictionary, are the set of words a language offers its users.

A language's syntax is the set of rules used to determine if a certain statement is valid within the language.

Semantics are a set of rules that determine whether or not a given phrase makes sense in a language.

The 4 language elements are:

1. An alphabet
2. A lexis/dictionary
3. Syntax Rules
4. Semantics

Compiled code is translated to assembly language via the compiler. The computer's architecture then translates the assembly language to machine language. This means to run a program requires an initial time investment (to translate to machine language) but runs quickly on subsequent runs. Interpreted code (aka scripts) is code that is fed into an application (the interpreter) which executes the code without needing to translate the source code into machine language. This makes running and testing scripts quicker initially, but because the interpreter has to talk to the machine on every run, the code is slower than an identical, compiled version of the code.

The contrasting pros/cons of compiled vs. interpreted code are thus:

1. Compiled code is faster in subsequent executions than interpreted code as the code is already in machine language.
2. Interpreted code is easier to debug/modify as the code does not need to be recompiled after every change.
3. Compiled code can run on any machine that uses the same architecture as the architecture in which the compiled code is compiled.
4. Interpreted code is architecture independent, but does require the interpreter program to be installed on any client system that will run the code.

A function is a distinct unit of code that can perform an actions and optionally return information to the caller (the code that calls the function).

A function invocation consists of:

1. The function name
2. Parentheses
3. The argument list

The interpreter performs the following actions:

1. Check that the function name is legal/exists
2. Ensures that the number of arguments supplied conform to the number of arguments required for the function
3. Interpreter passes flow control to the function block
4. Evaluates the function
5. Returns flow control to the caller

The print() function takes a variable-length list of variant type objects and sends them to the selected output device to be displayed.

The print() function expects a list of 0 or more objects that can be output to a console.

An instruction is a specific command that can be evaluated by the Python interpreter. Instructions can flow onto multiple lines in the Python IDE, but multiple instructions cannot be contained on the same line.

The escape character is the backslash (\) character, and it tells the interpreter that the character following the backslash should not be considered part of a string literal, but rather a specific character (new line) or formatting instruction.

\n

\\