实验1
四、实验结论
1.实验任务1
task1_1.py
print('hey, u') print('hey', ' u') x,y,z = 1,2,3 print(x, y, z) print('x = %d, y = %d, z = %d' %(x,y,z)) print('x = {}, y = {}, z = {}'.format(x,y,z)) print(f'x = {x}, y = {y}, z = {z}') print(x) print(y) print(z) print(x, end=' ') print(y, end=' ') print(z)
task1_2.py
x1, y1 = 1.2, 3.57 x2, y2 = 2.26, 8.7 print('{:-^40}'.format('输出1')) print('x1 = {}, y1 = {}'.format(x1, y1)) print('x2 = {}, y2 = {}'.format(x2, y2)) print('{:-^40}'.format('输出2')) print('x1 = {:.1f}, y1 = {:.1f}'.format(x1, y1)) print('x2 = {:.1f}, y2 = {:.1f}'.format(x2, y2)) print('{:-^40}'.format('输出3')) print('x1 = {:<15.1f}, y1 = {:<15.1f}'.format(x1, y1)) print('x2 = {:<15.1f}, y2 = {:<15.1f}'.format(x2, y2)) print('{:-^40}'.format('输出3')) print('x1 = {:>15.1f}, y1 = {:>15.1f}'.format(x1, y1)) print('x2 = {:>15.1f}, y2 = {:>15.1f}'.format(x2, y2))
task1_3.py
name1, age1 = 'Bill', 19 name2, age2 = 'Hellen', 18 title = 'Personnel Information' print(f'{title:=^40}') print(f'name: {name1:10}, age: {age1:3}') print(f'name: {name2:10}, age: {age2:3}') print(40*'=')
实验一（总结）：
print输出的几种用法:
1.输出单个字符串或单个变量 2.输出多个数据项，用逗号分隔 3.用户混合字符串和变量值 4.换行
2.实验任务2
task2_1.py
r1 = eval('1 + 2') print(type(r1), r1) r2 = eval('[1, 6, 7.5]') print(type(r2), r2) r3 = eval('"python"') print(type(r3), r3) r4 = eval('7, 42') print(type(r4), r4)
task2_2.py
x, y = eval(input('Enter two oprands: ')) ans = x + y print(f'{x} + {y} = {ans}') print(f'{type(x)} + {type(y)} = {type(ans)}')
函数eval()的用法:
1.把字符串转换为python表达式，相当于把圆括号中内容两侧的引号去掉 2.组合使用内置函数eval()和input()
3.实验任务3
task3.py
ans1 = 0.1 + 0.2 print(f'0.1 + 0.2 = {ans1}') from decimal import Decimal ans2 = Decimal('0.1') + Decimal('0.2') print(f'0.1 + 0.2 = {ans2}')
line4存在误差：二进制计算中浮点数无法精确表示，只能舍入后存储
Decimal运算：基于整数或浮点数构造将执行该整数或浮点值的精确转换，以十进制方法计算，因此不会产生二进制计算中的误差。
4.实验任务4
task4.py
print(chr(0x1f600), end = " ") print(chr(0x1f601), end = " ") print(chr(0x1f602), end = " ") print(chr(0x1f603), end = " ") print(chr(0x1f604)) print(chr(10000), end=" ") print(chr(0x025b), end=" ") print(chr(0x2708), end=" ") print(chr(0x00A5), end=" ") print(chr(0x266b)) print(ord('a'), end = " ") print(ord('b'), end = " ") print(ord('c')) print(ord('A'), end = " ") print(ord('B'), end = " ") print(ord('C')) print(ord('0'), end = " ") print(ord('1'), end = " ") print(ord('2'))
chr()和ord()作用:
ord函数返回一个字符对应的unicode编码，chr函数反过来，返回一个unicode编码对应的字符
5.实验任务5
task5_1.py
from math import sqrt n = float(input('输入一个数:')) ans1 = sqrt(n) ans2 = n**0.5 print('%.2f的平方根是: %.2f' %(n, ans1)) print('{:.2f}的平方根是: {:.2f}'.format(n, ans2)) print(f'{n:.2f}的平方根是: {ans2:.2f}')
task5_2.py
from math import pi text = ''' 好奇心是人的天性。 理想情况下，学习新东西是让人愉快的事。 但学校里的学习似乎有点像苦役。 有时候，需要画一个大饼，每次尝试学一些新鲜的，才会每天变得更好一点点。 ''' print(text) r = float(input('给学习画一个大饼，大饼要做的很大，半径要这么大: ')) circle = 2*pi*r print(f'绕起来，大饼的圆周有这么长, {circle}, 够不够激发你探索未知的动力...')
6.实验任务6
task6.py
x=float(input("从键盘输入：")) y=x**(365) print(x,"的365次方:",y)
7.实验任务7
task7.py
from math import pi from math import log p=1.038 c=3.7 K=5.4*10**(-3) M=67 Tw=100 Ty=70 To=float(input("从键盘输入To=：")) t=(M**(2/3)*c*p**(1/3))/(K*pi**2*((4*pi)/3)**(2/3))*log(0.76*((To-Tw)/(Ty-Tw))) print(f"To={To}°C,t={t//60}分{t%60}秒"
五、实验总结
·print(),eval(),chr(),ord()的用法，二进制浮点运算出现误差的原因，python的简洁，复杂函数的运算等
·切实感受了各种代码，同时又加深了一次对他们的记忆。但是还没有完全记好它们的用法
·分享：花了2万多买的Python教程全套，现在分享给大家，入门到精通(Python全栈开发教程)_哔哩哔哩_bilibili8 b站的python教程
