python期中考试知识点_python 中的一些小练习 【3】 ლ(╹◡╹ლ)

正好在复习期中考试，顺带就把课上做的笔记，还有老师写的一些比较tricky问题的代码po上来供大家参考，这样一来二去，自己也算是复习了一遍ლ(╹◡╹ლ) and 希望我周六能考一个好成绩( •̀ .̫ •́ )✧

问题1: Find the sum of all the multiples of 3 or 5 below 1000.

计算1000以下能被3或5整除的数字的和。

#代码：

tot_sum = 0

for i in range(1,1000):

if (i%3 == 0 or i%5 == 0):

tot_sum += i

print(tot_sum)

问题2： Write a function that accepts a sub-total from a restaurant bill, with an optional tip value defaulting to 18% and optional tax value defaulting to 10%, returning the final bill. Test the function with the default values and with 20% tip and 10.5% tax。

自动计算营业额的公式

def total_bill(sub_total,tip=0.18,tax=0.10):

return sub_total*(1+tip+tax)

问题3:Consider a stock with a price today of $p. For n consecutive days, it follows a path with two components: a drift of $c/day and a uniformly-distributed random variable of +/- $v/day. Write a function to calculate the series of prices and plot them.

import numpy as np

import matplotlib.pyplot as plt

series_values = list()

def series_calc(stock_price,no_days,drift,v):

days_X = list()

days_X.append(0)

series_values.append(stock_price)

for ii in range (0,no_days):

days_X.append(ii+1)

randomV=np.random.uniform(low=-v,high=v,size=None)

stock_price += (drift + randomV)

series_values.append(stock_price)

plt.plot(days_X,series_values)

plt.show()

series_calc(100,1000,0.1,10.0)

问题4 ： Write a program to generate a dictionary that contains (n,n*n) as key-value pairs from keys ranging from 0 to m.

dict1={}

m=10

for n in range(0,m):

dict1[n]=n*n

print(dict1)

问题5:Write a program that asks a user for a long string containing multiple words. Print back the original string, but with the words in backwards order.

把一串文字用倒序方式呈现出来

sentence = "hello there"

words = sentence.split()

sentence_rev = " ".join(reversed(words))

print(sentence_rev)

问题6:Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

对斐波那契数列求和，只求偶数的和。

tot_sum = 0

def fib(n):

ex4 = list()

a, b = 1, 1

while b < n:

ex4.append(b)

a, b = b, a+b

return ex4

ex4_fib = fib(4000000)

print(ex4_fib)

for i in ex4_fib:

if i%2 == 0:

tot_sum += i

print(tot_sum)