练习51:
题目:
学习使用 按位与(&) 。
分析:
0&0=0; 0&1=0; 1&0=0; 1&1=1。
程序:
if __name__ == \'__main__\':
a = 8
b = a & 4
print(\'a & b = %d\' % b)
b &= 2
print(\'a & b = %d\' % b)
输出结果:
a & b = 0
a & b = 0
练习52:
题目:
学习使用 按位或(|) 。
分析:
0|0=0; 0|1=1; 1|0=1; 1|1=1
程序:
if __name__ == \'__main__\':
a = 12
b = a | 3
print(\'a | b is %d\' % b)
b |= 7
print(\'a | b is %d\' % b)
输出结果:
a | b is 15
a | b is 15
练习53:
题目:
学习使用 按位异或(^) 。
分析:
0^0=0; 0^1=1; 1^0=1; 1^1=0
程序:
if __name__ == \'__main__\':
a = 12
b = a ^ 3
print(\'The a ^ 3 = %d\' % b)
b ^= 7
print(\'The a ^ b = %d\' % b)
输出结果:
The a ^ 3 = 15
The a ^ b = 8
练习54:
题目:
取一个整数 a 从右端开始的 4~7位。
分析:
可以这样考虑:
(1) 先使a右移4位。
(2) 设置一个低4位全为1,其余全为0的数。可用(0<<4)
(3) 将上面二者进行 与运算(&)。
程序:
if __name__ == \'__main__\':
a = int(input(\'input a number:\\n\'))
b = a >> 4
c = ~(~0 << 4)
d = b & c
print(\'%o\\t%o\' % (a, d))
输出结果:
input a number:
23
27 1
练习55:
题目:
学习使用 按位取反(~)。
分析:
0=1;1=0;
(1) 先使a右移4位。
(2) 设置一个低4位全为1,其余全为0的数。可用(0<<4)
(3) 将上面二者进行&运算。
程序:
if __name__ == \'__main__\':
a = 234
b = ~a
print(\'The a\\\'s 1 complement is %d\' % b)
a = ~a
print(\'The a\\\'s 2 complement is %d\' % a)
输出结果:
The a\'s 1 complement is -235
The a\'s 2 complement is -235
练习56:
题目:
画图,学用circle画圆形。
程序:
if __name__ == \'__main__\':
from Tkinter import *
canvas = Canvas(width=800, height=600, bg=\'yellow\')
canvas.pack(expand=YES, fill=BOTH)
k = 1
j = 1
for i in range(0, 26):
canvas.create_oval(310 - k, 250 - k, 310 + k, 250 + k, width=1)
k += j
j += 0.3
mainloop()
练习57:
题目:
画图,学用line画直线。
程序:
if __name__ == \'__main__\':
from Tkinter import *
canvas = Canvas(width=300, height=300, bg=\'green\')
canvas.pack(expand=YES, fill=BOTH)
x0 = 263
y0 = 263
y1 = 275
x1 = 275
for i in range(19):
canvas.create_line(x0,y0,x0,y1, width=1, fill=\'red\')
x0 = x0 - 5
y0 = y0 - 5
x1 = x1 + 5
y1 = y1 + 5
x0 = 263
y1 = 275
y0 = 263
for i in range(21):
canvas.create_line(x0,y0,x0,y1,fill = \'red\')
x0 += 5
y0 += 5
y1 += 5
mainloop()
练习58:
题目:
画图,学用rectangle画方形。
程序:
rectangle(int left, int top, int right, int bottom)。
if __name__ == \'__main__\':
from Tkinter import *
root = Tk()
root.title(\'Canvas\')
canvas = Canvas(root,width = 400,height = 400,bg = \'yellow\')
x0 = 263
y0 = 263
y1 = 275
x1 = 275
for i in range(19):
canvas.create_rectangle(x0,y0,x1,y1)
x0 -= 5
y0 -= 5
x1 += 5
y1 += 5
canvas.pack()
root.mainloop()
练习59:
题目:
画图,综合例子。
分析:
利用for循环控制100-999个数,每个数分解出个位,十位,百位。
程序:
if __name__ == \'__main__\':
from Tkinter import *
canvas = Canvas(width=300, height=300, bg=\'green\')
canvas.pack(expand=YES, fill=BOTH)
x0 = 150
y0 = 100
canvas.create_oval(x0 - 10, y0 - 10, x0 + 10, y0 + 10)
canvas.create_oval(x0 - 20, y0 - 20, x0 + 20, y0 + 20)
canvas.create_oval(x0 - 50, y0 - 50, x0 + 50, y0 + 50)
import math
B = 0.809
for i in range(16):
a = 2 * math.pi / 16 * i
x = math.ceil(x0 + 48 * math.cos(a))
y = math.ceil(y0 + 48 * math.sin(a) * B)
canvas.create_line(x0, y0, x, y, fill=\'red\')
canvas.create_oval(x0 - 60, y0 - 60, x0 + 60, y0 + 60)
for k in range(501):
for i in range(17):
a = (2 * math.pi / 16) * i + (2 * math.pi / 180) * k
x = math.ceil(x0 + 48 * math.cos(a))
y = math.ceil(y0 + 48 + math.sin(a) * B)
canvas.create_line(x0, y0, x, y, fill=\'red\')
for j in range(51):
a = (2 * math.pi / 16) * i + (2 * math.pi / 180) * k - 1
x = math.ceil(x0 + 48 * math.cos(a))
y = math.ceil(y0 + 48 * math.sin(a) * B)
canvas.create_line(x0, y0, x, y, fill=\'red\')
mainloop()
练习60:
题目:
计算字符串长度。
程序:
s = \'strlen\'
print(len(s))
输出结果:
6
来源:https://www.cnblogs.com/youcans/p/14460348.html
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