Презентация на тему Simple data manipulation

used to calculate the arithmetic expression. For example, the

position of an object falling from sky currently at velocity 5 m/s after 0.6 seconds. The distance can be calculated from the equation, y(t) = v0t-0.5gt2.
It can be computed directly in Python:
Step 1: type 0.5*0.6 - 0.5*9.81*0.6**2
Step 2: hit enter and then, the answer will be displayed below
In Python, the four standard arithmetic operator are written as +, -, * and /. The exponentiation employs a double asterisk notation, e.g. 0.62 = 0.6**2.

begin with a letter
The name can contain only letters,

numbers, and the underscore character. No punctuation marks, spaces, or other special characters are allowed in the name.
The name cannot be a keyword in Python, e.g. if, for, print, float, while.
Names in Python are case sensitive.

it would be more informative to provide some comments

in a natural human language to explain the idea behind the statements. This helps the programmer to recall the details of the code later in time, or other programmers to understand her work. Comments start with # character, and everything after this character on a line is ignored when the program is run.

# Program for computing the height of a ball in vertical motion
v0 = 5 # initial velocity
g = 9.81 # acceleration of gravity
t = 6 # time

y = v0*t - 0.5*g*t**2 # vertical position

print y

shown on the screen with a command print y.

Instead of just printing the numerical values, suppose we now want to write a more informative text, typically some thing like
At t=0.6 s, the height of the ball is 1.23 m.
It can be produced by the statement:
print "At t=%g s, the height of the ball is %.2f m." % (t,y)
The print statement will print everything enclosed in quotes. % in quotes indicates the place to insert the values. g is the format in decimal or scientific notation and .2f format stands for 2 decimal floating-point number.

velocity
g = 9.81 # acceleration of gravity
t =

6 # time

y = v0*t - 0.5*g*t**2 # vertical position

print "At t=%g s, the height of the ball is %.2f m." % (t,y)

continue from a different window
Step 1: From the Python

Shell window, click file > New Window
Step 2: Making your code in the new window created
Step 3: From the new window, click file > save as > choose save as type (*py)
Step 4: From the new window, click run > Run Module or press to run the program
Step 5: Output will be displayed in the main Python Shell window

import print format specifications: