我有一个包含多个转义字符的相当大的字符串(想想\ n,\ xB7,...)。这些“特殊字符”作为字符序列存储在字符串中,而不是实际的特殊字符。简而言之,我需要一种方法将字符序列转换为它们所代表的实际特殊字符。
以下是我目前创建的一些示例:
from math import sqrt
from turtle import Turtle, Screen
SCALE = 300
ITERATIONS = 7
def draw_circle(turtle):
turtle.goto(0, -SCALE)
turtle.pendown()
turtle.circle(SCALE)
turtle.penup()
def inscribe_circle(turtle, sides, edge_length):
turtle.goto(0, -SCALE)
turtle.setheading(0)
turtle.left(180 / sides)
turtle.pendown()
for _ in range(sides):
turtle.forward(edge_length * SCALE)
turtle.left(360 / sides)
turtle.penup()
# based on code and analysis from http://www.craig-wood.com/nick/articles/pi-archimedes/
def pi_archimedes(turtle, n):
""" Calculate n iterations of Archimedes PI recurrence relation """
polygon_edge_length_squared = 2.0
polygon_edge_length = sqrt(polygon_edge_length_squared)
polygon_sides = 4
inscribe_circle(turtle, polygon_sides, polygon_edge_length)
print(polygon_sides * polygon_edge_length / 2)
for _ in range(n - 1):
polygon_sides *= 2
polygon_edge_length_squared = 2 - 2 * sqrt(1 - polygon_edge_length_squared / 4)
polygon_edge_length = sqrt(polygon_edge_length_squared)
inscribe_circle(turtle, polygon_sides, polygon_edge_length)
print(polygon_sides * polygon_edge_length / 2)
yertle = Turtle()
yertle.penup()
draw_circle(yertle)
pi_archimedes(yertle, ITERATIONS)
yertle.hideturtle()
Screen().exitonclick()
我需要替换所有字符序列,而不仅仅是\ n:
var seq = "\n"
//outputs "
// "
seq = "\\n"
// outputs "\n"
seq.replace(/\\\\/g, "\\")
// outputs "\n"