我有一个包含 x、y、z 值的文件。我希望找到一种优雅的方式来打开并向每一行添加新的值 id,然后再次保存同一文件。
def get_point_grid_id(x,y,x_min,y_max,x_dist,y_dist):
col = int((x - x_min)/x_dist)
row = int((y_max - y)/y_dist)
return (row, col)
例如
1 1 10
2 2 10
3 3 10
ID 将是
get_point_grid_id(1,1,0,10,1,1)
(9, 1)
get_point_grid_id(2,2,0,10,1,1)
(8, 2)
get_point_grid_id(3,3,0,10,1,1)
(7, 3)
新文件将是
1 1 10 (9, 1)
2 2 10 (8, 2)
3 3 10 (7, 3)
我正在 Stackoverflow 中阅读几种方法,并且测试了几种方法。我老实说我已经尝试过保存新文件但失败了。
我尝试了以下解决方案
with open(file_temp, "r+") as f:
for line in open(file_temp):
x,y,z = line.split()
id = get_point_grid_id(float(x),float(y),0,10,1,1)
element = [x,y,z,id]
newelement = " ".join([str(e) for e in element])+ "\n"
f.write(newelement)
但我收到此错误消息
Traceback (most recent call last):
File "<editor selection>", line 3, in <module>
ValueError: too many values to unpack
其中 newelement(真实数据)是
'481499.55 6244324.75 19.15 (377, 2909)\n'
最佳答案
您可以通过 fileinput
模拟所需的行为模块,但请记住,它将在后台创建原始 10GB+ 文件的备份副本:
#! /usr/bin/env python
import fileinput
def get_point_grid_id(x,y,x_min,y_max,x_dist,y_dist):
col = int((x - x_min)/x_dist)
row = int((y_max - y)/y_dist)
return (row, col)
input_file = "test.dat"
#
# Add mode='rb' to the arguments of fileinput.input() if you are
# using a binary file on operating systems that differentiate
# between binary and text files (e.g. Microsoft Windows).
#
for line in fileinput.input(input_file, inplace=True):
columns = line.split()
if 3 == len(columns):
x, y, z = columns
id = get_point_grid_id(float(x),float(y),0,10,1,1)
print "{0} {1} {2} {3}".format(x, y, z, id)
传递给 fileinput.input
的 inplace
参数会触发魔法。
关于python读取文件,为每一行保存一个新列并保存相同的文件,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15030038/