Python: Write-Length Control

I am trying to create a specific output pattern for a textfile I wanted to later load into C++.
I wrote a file in Python that creates random coordinates and movement values in a circle.
The output is supposed to have the output:

   Place_1 Place_2 Place_3 Movement_1 Movement_2 Movement_3\n

   Place_1 Place_2 Place_3 Movement_1 Movement_2 Movement_3\n

   Place_1 Place_2 Place_3 Movement_1 Movement_2 Movement_3

The Code is use is

import numpy as np
file = open('log.txt', 'a')


def f(n, center, radius, ecc):
  pos = np.zeros((n,6))
  r = ecc * radius
  for i in range(n):
    while 1:
        x_1 = -1 + 2 * np.random.rand(1)
        x_2 = -1 + 2 * np.random.rand(1)
        if (x_1*x_1 + x_2*x_2)<1 :
            pos[i,0] = center[0] + r * 2 * x_1 * np.sqrt(1 - x_1*x_1 - x_2*x_2)
            pos[i,1] = center[1] + r * 2 * x_2 * np.sqrt(1 - x_1*x_1 - x_2*x_2)
            pos[i,2] = center[2] + r * (1 - 2 * (x_1*x_1 + x_2*x_2))
            pos[i,3] = (-1 + 2 * np.random.rand(1))
            pos[i,4] = (-1 + 2 * np.random.rand(1))
            pos[i,5] = (-1 + 2 * np.random.rand(1))
            break
    string = str(pos[i,:]).strip('[]').rstrip('\n')
    file.write(string)
  return

f(10000, np.array((127,127,127)), 92, 0.9)

file.close()

The log I create is however very badly formated. How can I get the required format?

>Solution :

You’re going to a lot of trouble here that you don’t need. This seems to solve the problem, simply.

import numpy as np
file = open('log.txt', 'a')

def f(n, center, radius, ecc):
    r = ecc * radius
    for i in range(n):
        while 1:
            pos = [0]*6
            x_1 = -1 + 2 * np.random.rand(1)[0]
            x_2 = -1 + 2 * np.random.rand(1)[0]
            if (x_1*x_1 + x_2*x_2) < 1:
                pos[0] = center[0] + r * 2 * x_1 * np.sqrt(1 - x_1*x_1 - x_2*x_2)
                pos[1] = center[1] + r * 2 * x_2 * np.sqrt(1 - x_1*x_1 - x_2*x_2)
                pos[2] = center[2] + r * (1 - 2 * (x_1*x_1 + x_2*x_2))
                pos[3] = (-1 + 2 * np.random.rand(1)[0])
                pos[4] = (-1 + 2 * np.random.rand(1)[0])
                pos[5] = (-1 + 2 * np.random.rand(1)[0])
                break
        print(*pos, file=file)

f(10000, np.array((127,127,127)), 92, 0.9)

file.close()

A solution without numpy:

import math
import random
file = open('log.txt', 'a')

def f(n, center, radius, ecc):
    r = ecc * radius
    for _ in range(n):
        pos = [0]*6
        while 1:
            x_1 = 2 * random.random() - 1
            x_2 = 2 * random.random() - 1
            vector = x_1*x_1 + x_2*x_2
            if vector < 1:
                break
        pos[0] = center[0] + r * 2 * x_1 * math.sqrt(1 - vector)
        pos[1] = center[1] + r * 2 * x_2 * math.sqrt(1 - vector)
        pos[2] = center[2] + r * (1 - 2 * vector)
        pos[3] = 2 * random.random() -1
        pos[4] = 2 * random.random() -1
        pos[5] = 2 * random.random() -1
        print(*pos, file=file)

f(10000, (127,127,127), 92, 0.9)

file.close()