Calculation loop process control of the fourth week python, randow library, pi

table of Contents

Through the loop by the number of cycles, a structure traversal circulation operation is formed

Infinite loop:

randow library (random number generation)

Pi Calculated:

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Through the loop , the number of press cycles through the loop structure formed of a Run

for <loop variable> in <traverse Structure>:

    <Statement block>

Each cycle, the resulting element into the loop variable, and executes a block of statements;

Counting cycle:

for i in range(N)#执行n次，每次i+1
    <语句块>

for i in range(M,N,K)#执行特定次，N-M次，步长为K
    <语句块>

String traversal cycle:

for c in s:#s是字符串，遍历完每个字符截止
    <语句块>

List traversal cycle:

for item in ls :#ls是一个列表，遍历其每个元素
    <语句块>

File traversal cycle

for line in fi:#fi是一个标识符，遍历其每行
    <语句块>

Infinite loop:

while <条件>：

     <Statement block>

Reserved words, BREAK, the Continue , with c

Advanced Usage:

while<条件>：
    <语句块>
else：
    <语句块>#for循环一样可以用，若循环里没有发生break退出，即执行else的内容

randow library (random number generation)

Substantially random number function: seed (seed) in generating a random number seed corresponding to the reproducible results random (): generates a decimal from 0.0 to 1.0

randint (a, b) generating an integer between ab

randrange (m, n [, k ]) between mn, in steps of k

getrandbits (k) to generate a random number k bit long

Uniform (A, B) , a random decimal between ab

choice (seq) from a randomly selected sequence number

shuffle (seq) in which the elements are arranged randomly

Pi Calculated:

#蒙特卡洛方法算圆周率
from random import random
from time import perf_counter
DARTS = 1000*10000
hits = 0.0
start = perf_counter()
for i in range(DARTS):
    x,y = random(),random()
    dist = pow(x ** 2 + y ** 2,0.5)
    if dist <= 1.0:
        hits += 1
pi = 4 *(hits/DARTS)
print("圆周率为{}",format(pi))
print(“程序运行的时间为：{}”format（perf_counter()-start）)