The interpreter

The Python command's interpreter launched by the command with the same name. The prompt >>> shows when the interpreter waits for a command. Another prompt … tells the user that the next command will belong to the current block. A block of command ends generally by an empty line. The tutorial's examples use the interpreter prompts to make the difference between commands and their output.

Comment

A comment in Python begin with a # (cardinal) and finish at the end of line.

Example :

# This is a comment

Variables Overview

The variable's names are case sensitive. The variable Toto is not the same as TOTO. A variable exists only when assign. The assign gives the kind of variable and its value. Assigns an existing variable allows the change of its type.

Example :

>>> A=0
>>> print A
0
>>> A+=1
>>> print A
1

>>> A=0
>>> a=2
>>> print A
0

>>> A=0
>>> print A
0
>>> A= "titi"
>>> A+=1
"cannot concatenate 'str' and 'int' objects"

Integer Variable

An integer variable is created by the assignment of an integer or by the int() function.

Example :

>>> A=0
>>> print A
0

>>> A=int("0")
>>> print A
0

Floating Variable

A floating variable is created when the formula assigns contains at least one floating number or by using the float() function.

Example :

>>> A=5.0
>>> print A
5.0

>>> A=5+.0
>>> print A
5.0

>>> A=float("0")
>>> print A
0.0

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