Question

我要学习Python大约4个小时，所以这可能是一个非常愚蠢的问题。

我不太了解为什么测地线对于我提供的2个坐标之间的距离返回0.0。

import csv
from geopy.distance import geodesic

with open('sample_data.csv', mode='r') as csv_file:

csv_reader = csv.DictReader(csv_file)

line_count = 0

coordinate_set = 1

coordinates_1 = 0
coordinates_2 = 0

for row in csv_reader:

    if line_count == 0:
        line_count += 1
        continue

    else:

        print("------------------------------------")
        print(line_count)

        if coordinate_set == 1:
            # added cast to float as per recommendation from IftahP
            coordinates_1 = (float(row['Lat']),float(row['Long']))
            # coordinate_set_1 = (41.49008, -71.312796)
            print("Set 1: ")
            print(coordinate_set_1)
            coordinate_set = 2

        if coordinate_set == 2:
            # added cast to float as per recommendation from IftahP
            coordinates_2 = (float(row['Lat']),float(row['Long']))
            #coordinate_set_2 = (41.499498, -81.695391)
            print("Set 2: ")
            print(coordinates_2)

            ## Distance between the 2 coordinates
            print(coordinates_1,coordinates_2)
            print(geodesic(coordinates_1,coordinates_2).miles)

            coordinate_set = 1  

    line_count += 1

这是输出...

------------------------------------
1
Set 1: 
('26.0595233', '-80.1332766')
Set 2: 
(25.458595, -80.20754)
(25.458595, -80.20754) (25.458595, -80.20754)
0.0
------------------------------------
2
Set 1: 
('26.0595233', '-80.1332766')
Set 2: 
(25.4586116, -80.207505)
(25.4586116, -80.207505) (25.4586116, -80.207505)
0.0
------------------------------------
3
Set 1: 
('26.0595233', '-80.1332766')
Set 2: 
(25.4586083, -80.2075033)
(25.4586083, -80.2075033) (25.4586083, -80.2075033)
0.0
------------------------------------
4
Set 1: 
('26.0595233', '-80.1332766')
Set 2: 
(25.4585966, -80.2075216)
(25.4585966, -80.2075216) (25.4585966, -80.2075216)
0.0
------------------------------------
5
Set 1: 
('26.0595233', '-80.1332766')
Set 2: 
(25.4585883, -80.20755)
(25.4585883, -80.20755) (25.4585883, -80.20755)
0.0
------------------------------------
6
Set 1: 
('26.0595233', '-80.1332766')
Set 2: 
(25.4585833, -80.2075316)
(25.4585833, -80.2075316) (25.4585833, -80.2075316)
0.0
------------------------------------
7
Set 1: 
('26.0595233', '-80.1332766')
Set 2: 
(25.4585833, -80.207495)
(25.4585833, -80.207495) (25.4585833, -80.207495)
0.0
------------------------------------
8
Set 1: 
('26.0595233', '-80.1332766')
Set 2: 
(25.4585783, -80.2074866)
(25.4585783, -80.2074866) (25.4585783, -80.2074866)
0.0
------------------------------------

我“硬编码” https://pypi.org/project/geopy/上提供的坐标，当我使用它们时，它会显示一个距离。它只是不喜欢我输入的坐标。没有显示错误信息。

Answer 1

问题：coordinate_1和coordinate_2都是从同一个row读取的（因此距离始终等于0）

解决方案是在coordinate_set个周期内将开关if的值从row s中移出：

for row in csv_reader:
    if coordinate_set == 1:
        coordinates_1 = (float(row['Lat']),float(row['Long']))

        # coordinate_set = 2 ## 1st source of error

    if coordinate_set == 2:
        coordinates_2 = (float(row['Lat']),float(row['Long'])) # the same row is readen twice
        print(geodesic(coordinates_1,coordinates_2).miles)
        # coordinate_set = 1  ## 2nd error

    coordinate_set = 2 if (coordinate_set==1) else 1 # Correct switcher
    line_count += 1

为什么测地线返回0.0？

1 个答案: