输入一个正数，以下代码编程求出它的平方根。请你补全代码。
in_var = float(input("请输入一个需要开方的正数，可以使用2位小数：\n x = "))
if in_var < 0:
x = - in_var
else:
x = in_var
low = 0.0
high = x
s_root = ①
if x > 0 and x < 1:
high = 1.0
low = 0
s_root = ②
if x >= 0:
while abs( ③ ) > 0.0001:
if x > 1.0:
if s_root ** 2 < x:
low = s_root
else:
high = s_root
s_root = ④
if x == 1.0 and x == 0.0:
s_root = x
else:
if s_root ** 2 < x:
low = s_root
else:
high = s_root
s_root = ⑤
if in_var >= 0:
print("所求数的平方根为：s_root = %.1f"%(s_root))