100 个 Python 小例子(练习题三)
前期练习:
实例051:按位与
题目:学习使用按位与 & 。
程序分析:0&0=0; 0&1=0; 1&0=0; 1&1=1
。
a=0o77 print(a) b=a&3 print(b) b=b&7 print(b)
实例052:按位或
题目:学习使用按位或 | 。
程序分析:0|0=0; 0|1=1; 1|0=1; 1|1=1
a=0o77 print(a|3) print(a|3|7)
实例053:按位异或
题目:学习使用按位异或 ^
。
程序分析:0^0=0; 0^1=1; 1^0=1; 1^1=0
a=0o77 print(a^3) print(a^3^7)
实例054:位取反、位移动
题目:取一个整数a从右端开始的4〜7位。
程序分析: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&运算。
a=int(input('输入一个数字: ')) b=0 # 0 b=~b # 1 b=b<<4 # 10000 b=~b # 1111 c=a>>4 d=c&b print('a:',bin(a)) print('b:',bin(b)) print('c:',bin(c)) print('d:',bin(d))
实例055:按位取反
题目:学习使用按位取反~。
程序分析:~0=1; ~1=0;
print(~234) print(~~234)
实例056:画圈
题目:画图,学用circle画圆形。
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(26): canvas.create_oval(310-k,250-k,310+k,250+k,width=1) k+=j j+=0.3 mainloop()
实例057:画线
题目:画图,学用line
画直线。
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()
实例058:画矩形
题目:画图,学用rectangle
画方形。
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()
实例059:画图(丑)
题目:画图,综合例子。
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()
实例060:字符串长度
题目:计算字符串长度。
s='zhangguang101' print(len(s))
例061:杨辉三角
题目:打印出杨辉三角形前十行。
def generate(numrows): r = [[1]] for i in range(1,numrows): r.append(list(map(lambda x,y:x+y, [0]+r[-1],r[-1]+[0]))) return r[:numrows] a=generate(10) for i in a: print(i)
实例062:查找字符串
题目:查找字符串。
s1='aabbxuebixuebi' s2='ab' s3='xue' print(s1.find(s2)) print(s1.find(s3))
实例063:画椭圆
题目:画椭圆。
程序分析:使用 tkinter
。
if __name__ == '__main__': from tkinter import * x = 360 y = 160 top = y - 30 bottom = y - 30 canvas = canvas(width = 400,height = 600,bg = 'white') for i in range(20): canvas.create_oval(250 - top,250 - bottom,250 + top,250 + bottom) top -= 5 bottom += 5 canvas.pack() mainloop()
实例64:画椭圆、矩形
题目:利用ellipse
和 rectangle
画图。。
if __name__ == '__main__': from tkinter import * canvas = canvas(width = 400,height = 600,bg = 'white') left = 20 right = 50 top = 50 num = 15 for i in range(num): canvas.create_oval(250 - right,250 - left,250 + right,250 + left) canvas.create_oval(250 - 20,250 - top,250 + 20,250 + top) canvas.create_rectangle(20 - 2 * i,20 - 2 * i,10 * (i + 2),10 * ( i + 2)) right += 5 left += 5 top += 10 canvas.pack() mainloop()
实例065:画组合图形
题目:一个最优美的图案。
import math from tkinter import * class pts: def __init__(self): self.x = 0 self.y = 0 points = [] def linetodemo(): screenx = 400 screeny = 400 canvas = canvas(width = screenx,height = screeny,bg = 'white') aspectratio = 0.85 maxpts = 15 h = screeny w = screenx xcenter = w / 2 ycenter = h / 2 radius = (h - 30) / (aspectratio * 2) - 20 step = 360 / maxpts angle = 0.0 for i in range(maxpts): rads = angle * math.pi / 180.0 p = pts() p.x = xcenter + int(math.cos(rads) * radius) p.y = ycenter - int(math.sin(rads) * radius * aspectratio) angle += step points.append(p) canvas.create_oval(xcenter - radius,ycenter - radius, xcenter + radius,ycenter + radius) for i in range(maxpts): for j in range(i,maxpts): canvas.create_line(points[i].x,points[i].y,points[j].x,points[j].y) canvas.pack() mainloop() if __name__ == '__main__': linetodemo()
实例066:三数排序
题目:输入3个数a,b,c,按大小顺序输出。
程序分析:同实例005。
raw=[] for i in range(3): x=int(input('int%d: '%(i))) raw.append(x) for i in range(len(raw)): for j in range(i,len(raw)): if raw[i]>raw[j]: raw[i],raw[j]=raw[j],raw[i] print(raw) raw2=[] for i in range(3): x=int(input('int%d: '%(i))) raw2.append(x) print(sorted(raw2))
实例067:交换位置
题目:输入数组,最大的与第一个元素交换,最小的与最后一个元素交换,输出数组。
li=[3,2,5,7,8,1,5] li[-1],li[li.index(min(li))]=li[li.index(min(li))],li[-1] m=li[0] ind=li.index(max(li)) li[0]=li[ind] li[ind]=m print(li)
实例068:旋转数列
题目:有n个整数,使其前面各数顺序向后移m个位置,最后m个数变成最前面的m个数
from collections import * li=[1,2,3,4,5,6,7,8,9] deq=deque(li,maxlen=len(li)) print(li) deq.rotate(int(input('rotate:'))) print(list(deq))
实例069:报数
题目:有n个人围成一圈,顺序排号。从第一个人开始报数(从1到3报数),凡报到3的人退出圈子,问最后留下的是原来第几号的那位。
if __name__ == '__main__': nmax = 50 n = int(input('请输入总人数:')) num = [] for i in range(n): num.append(i + 1) i = 0 k = 0 m = 0 while m < n - 1: if num[i] != 0 : k += 1 if k == 3: num[i] = 0 k = 0 m += 1 i += 1 if i == n : i = 0 i = 0 while num[i] == 0: i += 1 print(num[i])
实例070:字符串长度ii
题目:写一个函数,求一个字符串的长度,在main
函数中输入字符串,并输出其长度。
def lenofstr(s): return len(s) print(lenofstr('tanxiaofengsheng'))
实例071:输入和输出
题目:编写input()
和output()
函数输入,输出5个学生的数据记录。
n = 3 #stu # num : string # name : string # score[4]: list student = [] for i in range(5): student.append(['','',[]]) def input_stu(stu): for i in range(n): stu[i][0] = input('input student num:\n') stu[i][1] = input('input student name:\n') for j in range(3): stu[i][2].append(int(input('score:\n'))) def output_stu(stu): for i in range(n): print ('%-6s%-10s' % ( stu[i][0],stu[i][1] )) for j in range(3): print ('%-8d' % stu[i][2][j]) if __name__ == '__main__': input_stu(student) print (student) output_stu(student)
实例072:创建链表
题目:创建一个链表。
class node: def __init__(self, data): self.data = data self.next = none def get_data(self): return self.data class list: def __init__(self, head): self.head = head def is_empty(self): return self.get_len() == 0 def get_len(self): length = 0 temp = self.head while temp is not none: length += 1 temp = temp.next return length def append(self, node): temp = self.head while temp.next is not none: temp = temp.next temp.next = node def delete(self, index): if index < 1 or index > self.get_len(): print("给定位置不合理") return if index == 1: self.head = self.head.next return temp = self.head cur_pos = 0 while temp is not none: cur_pos += 1 if cur_pos == index-1: temp.next = temp.next.next temp = temp.next def insert(self, pos, node): if pos < 1 or pos > self.get_len(): print("插入结点位置不合理") return temp = self.head cur_pos = 0 while temp is not node: cur_pos += 1 if cur_pos == pos-1: node.next = temp.next temp.next =node break temp = temp.next def reverse(self, head): if head is none and head.next is none: return head pre = head cur = head.next while cur is not none: temp = cur.next cur.next = pre pre = cur cur = temp head.next = none return pre def print_list(self, head): init_data = [] while head is not none: init_data.append(head.get_data()) head = head.next return init_data if __name__=='__main__': head=node('head') link=list(head) for i in range(10): node=node(i) link.append(node) print(link.print_list(head))
实例073:反向输出链表
题目:反向输出一个链表。
class node: def __init__(self, data): self.data = data self.next = none def get_data(self): return self.data class list: def __init__(self, head): self.head = head def is_empty(self): return self.get_len() == 0 def get_len(self): length = 0 temp = self.head while temp is not none: length += 1 temp = temp.next return length def append(self, node): temp = self.head while temp.next is not none: temp = temp.next temp.next = node def delete(self, index): if index < 1 or index > self.get_len(): print("给定位置不合理") return if index == 1: self.head = self.head.next return temp = self.head cur_pos = 0 while temp is not none: cur_pos += 1 if cur_pos == index-1: temp.next = temp.next.next temp = temp.next def insert(self, pos, node): if pos < 1 or pos > self.get_len(): print("插入结点位置不合理") return temp = self.head cur_pos = 0 while temp is not node: cur_pos += 1 if cur_pos == pos-1: node.next = temp.next temp.next =node break temp = temp.next def reverse(self, head): if head is none and head.next is none: return head pre = head cur = head.next while cur is not none: temp = cur.next cur.next = pre pre = cur cur = temp head.next = none return pre def print_list(self, head): init_data = [] while head is not none: init_data.append(head.get_data()) head = head.next return init_data if __name__=='__main__': head=node('head') link=list(head) for i in range(10): node=node(i) link.append(node) print(link.print_list(head)) print(link.print_list(link.reverse(head)))
实例074:列表排序、连接
题目:列表排序及连接。
程序分析:排序可使用sort()
方法,连接可以使用 + 号或 extend()
方法。
a=[2,6,8] b=[7,0,4] a.extend(b) a.sort() print(a)
例075:不知所云
题目:放松一下,算一道简单的题目。
if __name__ == '__main__': for i in range(5): n = 0 if i != 1: n += 1 if i == 3: n += 1 if i == 4: n += 1 if i != 4: n += 1 if n == 3: print (64 + i)
到此这篇关于100 个 python 小例子(练习题三)的文章就介绍到这了,更多相关 python 练习题内容请搜索以前的文章或继续浏览下面的相关文章希望大家以后多多支持!
推荐阅读
-
用Python输出一个杨辉三角的例子
-
PYTHON练习题 二. 使用random中的randint函数随机生成一个1~100之间的预设整数让用户键盘输入所猜的数。
-
for循环练习 打印4面三角形,99乘法表 ,打印1-100内整数 数字包含9跳过 每行输出5个 用空格分隔,按照从大到小的顺序输出4位数中的个位+百位=十位+千位的数字及个数
-
Python小程序练习三之迭代器小例子
-
Python Selenium结合使用的一个小例子
-
Python中网络UDP通信的一个小例子
-
100 个 Python 小例子(练习题三)
-
用Python输出一个杨辉三角的例子
-
css通用小笔记02??浮动、清除(三个例子)_html/css_WEB-ITnose
-
通过一个小例子帮助你理解正则化(附python代码)