import numpy as np
import matplotlib.pyplot as plt

t = np.linspace(0,2*np.pi,100)
x = []
y = []

for theta in t:
	x.append(np.cos(theta))
	y.append(np.sin(theta))

fig, ax = plt.subplots()

ax.plot(x,y,'o')

ax.grid(True)

ax.spines['left'].set_position('zero')
ax.spines['bottom'].set_position('zero')
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')

plt.show()