Python III
Mary PW Chin 钱碧慧博士
Conditionals & random numbers
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Synopsis
The import keyword;
module random and its method randint ;
conditionals: if-elif-else ;
relational operators;
assignment vs comparison;
booleans operators, and vs or ;
variable names: rules and conventions e.g. camel-case;
output to screen (standard output) vs output to file;
Linux commands and options: ls , wc , head , tail ;
basic probability theory;
initialisation, counters and normalisation;
dir ;
more flowcharting.
Exercise
For the program on slide #19 mark out the:
variable names;
arguments;
functions;
keywords;
modules;
methods;
Repeat Exercise 1 for the program on slide #23.
Repeat Exercise 1 for the program on slide #35.
Is each of the following a legal variable name in Python?
mickey-mouse;
mickey.mouse;
mickey mouse;
2mickey mice.
Refer to the program on slide #35. What difference would you expect if we change
range(-100, so_many_times-100) ;
range(so_many_times+1000, 1000, -1) ;
range(0, so_many_times*1000, 1000) ?
Refer the program on slide #38. What happens if we change elif to if ? Draw the revised flowchart.
Write a program to generate two random numbers between 0 and 100. Print the larger number, and the sum, difference and product of the two numbers.
Write a program to generate a random number between 0 and 10. Take the number as the radius of a circle. Print the diameter, circumference and area of this circle. You can get the value for π by first importing the math module; the value for π is then accessible as math.pi .
Write a program to generate a random number between 0 and 100,
take the random number as a temperature in celsius, convert that to fahrenheit;
take the random number as a measurement in centimetres, convert to and inches;
take the random numner as a weight in kilograms, convert to pounds.
Write a program simulating the draw of Magnum 4D first prize.
What we have learned so far
Python keywords:
for
in
import
as
if
elif
else
and
or
Python built-in functions:
print(…, end='…')
range(…, …, …)
help(…)
dir(…)
Python modules and methods:
random.randint(…, …)
math.pi
Linux commands (and options):
