1. for line in sys.stdin:
import sys
sys.stdout.write('根据两点坐标计算直线斜率k，截距b：\n')
for line in sys.stdin:
if line == '\n': break
x1, y1, x2, y2 = (float(x) for x in line.split())
k = (y2 - y1) / (x2 - x1)
b = y1 - k * x1
sys.stdout.write('斜率:{}，截距:{}\n'.format(k, b))
2. while True:
line = sys.stdin.readline()
import sys
sys.stdout.write('根据两点坐标计算直线斜率k，截距b：\n')
while True:
line = sys.stdin.readline()
if line == '\n': break
x1, y1, x2, y2 = (float(x) for x in line.split())
k = (y2 - y1) / (x2 - x1)
b = y1 - k * x1
sys.stdout.write('斜率:{}，截距:{}\n'.format(k, b))
3. while True:
line = input()
print('根据两点坐标计算直线斜率k，截距b：')
while True:
line = input()
if line == '\n': break
x1, y1, x2, y2 = (float(x) for x in line.split())
k = (y2 - y1) / (x2 - x1)
b = y1 - k * x1
print('斜率:{}，截距:{}'.format(k, b))
