Python斐波那契数列

时间:2022-09-28 lxw-pro 人气:0

斐波那契数列——经典例子，永不过时！！！

1.for循环

def fibonacci1(n):
    a, b = 0, 1
    for i in range(n):
        a, b = b, a+b
        print(a)


fibonacci1(3)

或

def fib1(w):
    a, b = 1, 1
    for i in range(w-1):
        a, b = b, a+b
    return a

print(fib1(3))

[^1]刚好得出这个位置的数

2.while循环

def fibnaqi2(m):
    a, b = 0, 1
    i = 0
    while i < m:
        print(b)
        a, b = b, a+b
        i += 1

fibnaqi2(4)

[^1]刚好得出这个位置的数

3.使用递归

def fib2(q):
    if q == 1 or q == 2:
        return 1
    return fib2(q-1)+fib2(q-2)

print(fib2(9))

4.递归+for循环

def fibnacci3(p):
    lst = []
    for i in range(p):
        if i == 1 or i == 0:
            lst.append(1)
        else:
            lst.append(lst[i-1]+lst[i-2])
    print(lst)

fibnacci3(5)

5.递归+while循环

def fibnacci4(k):
    lis = []
    i = 0
    while i<k:
        if i == 0 or i == 1:
            lis.append(1)
        else:
            lis.append(lis[i-2]+lis[i-1])
        i += 1
    print(lis)

fibnacci4(6)

6.递归+定义函数+for循环

def fibnacci5(o):
    def fn(i):
        if i < 2:
            return 1
        else:
            return (fn(i-2)+fn(i-1))
    for i in range(o):
        print(fn(i))

fibnacci5(8)

7.指定列表

def fib3(e):
    if e == 1:
        return [1]
    if e == 2:
        return [1, 1]
    fibs = [1, 1]
    for i in range(2, e):
        fibs.append(fibs[-1]+fibs[-2])
    return fibs

print(fib3(12))

趣方程求解

题目描述

二次方程式 ax**2 + bx + c = 0 （a、b、c 用户提供，为实数，a ≠ 0）

# 导入 cmath(复杂数学运算) 模块
import cmath

a = float(input('输入 a: '))
b = float(input('输入 b: '))
c = float(input('输入 c: '))

# 计算
d = (b ** 2) - (4 * a * c)

# 两种求解方式
sol1 = (-b - cmath.sqrt(d)) / (2 * a)
sol2 = (-b + cmath.sqrt(d)) / (2 * a)

print('结果为 {0} 和 {1}'.format(sol1, sol2))

pandas 每日一练

# -*- coding = utf-8 -*-
# @Time : 2022/7/26 21:48
# @Author : lxw_pro
# @File : pandas -8 练习.py
# @Software : PyCharm

import pandas as pd
import numpy as np

df = pd.read_excel('text5.xlsx')
print(df)

print()

程序运行结果如下：

Unnamed: 0 Unnamed: 0.1 project ... test_time date time
0 0 00:00:00 Python ... 2022-06-20 18:30:20 2022-06-20 18:30:20
1 1 1 Java ... 2022-06-18 19:40:20 2022-06-18 19:40:20
2 2 2 C ... 2022-06-08 13:33:20 2022-06-08 13:33:20
3 3 3 MySQL ... 2021-12-23 11:26:20 2021-12-23 11:26:20
4 4 4 Linux ... 2021-12-20 18:20:20 2021-12-20 18:20:20
5 5 5 Math ... 2022-07-20 16:30:20 2022-07-20 16:30:20
6 6 6 English ... 2022-06-23 15:30:20 2022-06-23 15:30:20
7 7 7 Python ... 2022-07-19 09:30:20 2022-07-19 09:30:20
[8 rows x 7 columns]

41、将test_time列设置为索引

print(df.set_index('test_time'))

print()

程序运行结果如下：
Unnamed: 0 Unnamed: 0.1 ... date time
test_time ...
2022-06-20 18:30:20 0 00:00:00 ... 2022-06-20 18:30:20
2022-06-18 19:40:20 1 1 ... 2022-06-18 19:40:20
2022-06-08 13:33:20 2 2 ... 2022-06-08 13:33:20
2021-12-23 11:26:20 3 3 ... 2021-12-23 11:26:20
2021-12-20 18:20:20 4 4 ... 2021-12-20 18:20:20
2022-07-20 16:30:20 5 5 ... 2022-07-20 16:30:20
2022-06-23 15:30:20 6 6 ... 2022-06-23 15:30:20
2022-07-19 09:30:20 7 7 ... 2022-07-19 09:30:20
[8 rows x 6 columns]

42、生成一个和df长度相同的随机数dataframe

df1 = pd.DataFrame(pd.Series(np.random.randint(1, 10, 8)))
print(df1)

print()

程序运行结果如下：

0
0 1
1 3
2 2
3 7
4 7
5 3
6 5
7 1

43、将上一题生成的dataframe与df合并

df = pd.concat([df, df1], axis=1)
print(df)

print()

程序运行结果如下：

Unnamed: 0 Unnamed: 0.1 project ... date time 0
0 0 00:00:00 Python ... 2022-06-20 18:30:20 1
1 1 1 Java ... 2022-06-18 19:40:20 3
2 2 2 C ... 2022-06-08 13:33:20 2
3 3 3 MySQL ... 2021-12-23 11:26:20 7
4 4 4 Linux ... 2021-12-20 18:20:20 7
5 5 5 Math ... 2022-07-20 16:30:20 3
6 6 6 English ... 2022-06-23 15:30:20 5
7 7 7 Python ... 2022-07-19 09:30:20 1
[8 rows x 8 columns]

44、生成新的一列new为popularity列减去之前生成随机数列

df['new'] = df['popularity'] - df[0]
print(df)

print()

程序运行结果如下：

Unnamed: 0 Unnamed: 0.1 project popularity ... date time 0 new
0 0 00:00:00 Python 95 ... 2022-06-20 18:30:20 1 94
1 1 1 Java 92 ... 2022-06-18 19:40:20 3 89
2 2 2 C 145 ... 2022-06-08 13:33:20 2 143
3 3 3 MySQL 141 ... 2021-12-23 11:26:20 7 134
4 4 4 Linux 84 ... 2021-12-20 18:20:20 7 77
5 5 5 Math 148 ... 2022-07-20 16:30:20 3 145
6 6 6 English 146 ... 2022-06-23 15:30:20 5 141
7 7 7 Python 149 ... 2022-07-19 09:30:20 1 148
[8 rows x 9 columns]

45、检查数据中是否含有任何缺失值

jch = df.isnull().values.any()
print(jch)    # 运行结果为：False

print()

46、将popularity列类型转换为浮点数

fds = df['popularity'].astype(np.float64)
print(fds)

print()

程序运行结果如下：

0 95.0
1 92.0
2 145.0
3 141.0
4 84.0
5 148.0
6 146.0
7 149.0
Name: popularity, dtype: float64

47、计算popularity大于100的次数

cs = len(df[df['popularity'] > 100])
print(cs)    # 运行结果为：5

print()

48、查看project列共有几种学历

ckj = df['project'].nunique()
print(ckj)    # 运行结果为：7

print()

49、查看每科出现的次数

ckc = df.project.value_counts()
print(ckc)

print()

程序运行结果如下：

Python 2
Java 1
C 1
MySQL 1
Linux 1
Math 1
English 1
Name: project, dtype: int64

50、提取popularity与new列的和大于136的最后3行

df1 = df[['popularity', 'new']]
hh = df1.apply(np.sum, axis=1)
res = df.iloc[np.where(hh > 136)[0][-3:], :]
print(res)

程序运行结果如下：

Unnamed: 0 Unnamed: 0.1 project popularity ... date time 0 new
5 5 5 Math 148 ... 2022-07-20 16:30:20 3 145
6 6 6 English 146 ... 2022-06-23 15:30:20 5 141
7 7 7 Python 149 ... 2022-07-19 09:30:20 1 148
[3 rows x 9 columns]

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