- Variables
- Assignment Statements
- Data Types and Data Structure
- Arrays
- Flow of Control
- Input / Output
- Graphics
Tips
- // is floored division (In Python 2, '/' is the same as '//'. In Python 3, '/' is floating point division)
Example
import sys
import stdio
import math
a = int(sys.argv[1])
b = float(sys.argv[2])
c = float(sys.argv[3])
total = a + b
diff = a - b
prod = a * b
quot = a // b
rem = a % b
exp = a ** b
stdio.writeln(str(a) + ' // ' + str(b) + ' = ' + str(quot))
stdio.writeln(str(a) + ' % ' + str(b) + ' = ' + str(rem))
stdio.writeln(str(a) + ' ** ' + str(b) + ' = ' + str(exp))
discriminant = b*b - 4.0*c
d = math.sqrt(discriminant)
stdio.writeln((-b + d) / 2.0)
stdio.writeln((-b - d) / 2.0)
e = int (round (d))
# % import math
# % help(math)
# math.sin(), math.cos(), math.tan() = math.sin()/math.cos()
# Python functions:
# type() - returns type
# id() - returns id
# repr() - returns string representation of an object
# other built-in functions:
# max(), min(), sum(), float(), eval(), open(), file()
# boolean/logic
(not (a < b) and not (a > b))
if x > y:
maximum = x
else:
maximum = y
if random.randrange(0, 2) == 0:
stdio.writeln('Heads')
else:
stdio.writeln('Tails')
i = 4
while i <= 10:
stdio.writeln(str(i) + 'th Hello')
i = i + 1
for i in range(4, 11):
stdio.writeln(str(i) + 'th Hello')
for i in range(n+1):
stdio.writeln(str(i) + ' ' + str(power))
power *= 2
n = int(sys.argv[1])
for i in range(1, n+1):
# Write the ith line.
for j in range(1, n+1):
# Write the jth entry in the ith line.
if (i % j == 0) or (j % i == 0):
stdio.write('* ')
else:
stdio.write(' ')
stdio.writeln(i)
if income < 0: rate = 0.00
elif income < 8925: rate = 0.10
elif income < 36250: rate = 0.15
elif income < 87850: rate = 0.23
elif income < 183250: rate = 0.28
elif income < 398350: rate = 0.33
elif income < 400000: rate = 0.35
else: rate = 0.396
Arrays and Stdarray
x = [0.30, 0.60, 0.10]
y = [0.40, 0.10, 0.50]
suits = ['Clubs', 'Diamonds', 'Hearts', 'Spades']
total = 0.0
for i in range(n)
total += x[i]*y[i]
a = [] # creates an empty array
for i in range(n)
a += [0.0]
n = len(a)
for i in range(n // 2):
temp = a[i]
a[i] = a[n-1-i]
a[n-1-i] = temp
total = 0.0
for v in a:
total += v
average = total / len(a)
y = a # array aliasing
# the following is array copying
y = []
for v in x:
y += [v]
# array slicing
y = x[:]
# list
# numpy - to operate big array
# stdarray - create, read, write 2-d array
SUITS = ['Clubs', 'Diamonds', 'Hearts', 'Spades']
RANKS = ['2', '3', '4', '5', '6', '7', '8', '9', '10',
'Jack', 'Queen', 'King', 'Ace']
rank = random.randrange(0, len(RANKS))
suit = random.randrange(0, len(SUITS))
stdio.writeln(RANKS[rank] + ' of ' + SUITS[suit])
deck = []
for rank in RANKS:
for suit in SUITS:
card = rank + ' of ' + suit
deck += [card]
a = [[18, 19, 20], [21, 22, 23]]
# rectangular array
a = []
for i in range(m):
row = [0.0] * n
a += [row]
for i in range(m):
for j in range(n):
stdio.write(a[i][j])
stdio.write(' ')
stdio.writeln()
# same as
for row in a:
for v in row:
stdio.write(v)
stdio.write(' ')
stdio.writeln()
# matrix operation
c = stdarray.create2D(n, n, 0.0)
for i in range(n):
for j in range(n):
c[i][j] = a[i][j] + b[i][j]
c = stdarray.create2D(n, n, 0.0)
for i in range(n):
for j in range(n):
# Compute the dot product of row i and column j
for k in range(n):
c[i][j] += a[i][k] * b[k][j]
# ragged arrays
for i in range(len(a)):
for j in range(len(a[i])):
stdio.write(a[i][j])
stdio.write(' ')
stdio.writeln()
for row in a:
for v in row:
stdio.write(v)
stdio.write(' ')
stdio.writeln()
Stdio
- stdio.isEmpty()
- stdio.readInt(), stdio.readFloat(), stdio.readBool(), stdio.readString()
- stdio.hasNextLine()
- stdio.readLine()
- stdio.readAll(), stdio.readAllInts(), stdio.readAllFloats(), stdio.readAllBools()
- stdio.readAllStrings(), stdio.readAllLines()
# random sequence
import random
import sys
import stdio
n = int(sys.argv[1])
for i in range(n):
stdio.writeln(random.random())
# standard write/output functions
# stdio.write stdio.writeln stdio.writef
stdio.writef('pi is approximately %.2f\n', math.pi)
stdio.writef('The square root of %.1f is %.6f', c, t)
format = '%3s $%6.2f $%7.2f $%5.2f\n'
stdio.writef(format, month[i], pay, balance, interest)
# standard read/input functions
import sys
import stdio
n = int(sys.argv[1])
total = 0
for i in range(n):
total += stdio.readInt()
stdio.writeln('Sum is ' + str(total))
- Introduction to Programming in Python
- Python IDE for a day
- Python Code Download
- macports
- sudo python2.7 setup.py install
- Python on MAC
Useful Links
