Pyshp 将新字段附加到现有 shapefile 但不记录值

Question

问题在于将 .csv 文件中显示的列作为新字段附加到现有 shapefile。因此，我使用 Python 和模块 pyshp 和 csv 来首先复制原始 shapefile 的内容（几何和记录），其次，在此副本中创建新字段并在相应的 .csv 中迭代行以便在其上插入：

import os, sys
import shapefile, csv

from os.path import basename

filename_full = sys.argv[1]
output_full = sys.argv[2]

name, file_extension = os.path.splitext(filename_full)
output_name, file_extension = os.path.splitext(output_full)

filename_dbf =  name + ".dbf"
filename_classified =  name + "_classified.csv"
output_dbf =  output_name + ".dbf"

# reader
myshp = open(filename_full, "rb")
mydbf = open(filename_dbf, "rb")
r = shapefile.Reader(shp=myshp, dbf=mydbf)

# writer
w = shapefile.Writer(r.shapeType)

# copy shapefiles content
w._shapes.extend(r.shapes())
w.records.extend(r.records())
w.fields = list(r.fields)
w.save(output_full)

# add new records from the csv
with open(filename_classified, 'rt', encoding='utf-8') as csvfile:
     reader = csv.DictReader(csvfile, delimiter=',')    
     headers = reader.fieldnames
     [w.field(field) for field in headers]     
     for row in reader:            
        w.record(*tuple([row[f] for f in headers])) # <-- insertion in specific fields

w.save(output_full)

在 pyshp page 中，有几个示例。其中之一特定于将行插入特定字段。如下：

>>> w = shapefile.Writer()
>>> w.field('FIRST_FLD','C','40')
>>> w.field('SECOND_FLD','C','40')
>>> w.record('First', 'Line')
>>> w.record(FIRST_FLD='First', SECOND_FLD='Line')

但是，即使指示字段，我得到：

Traceback (most recent call last):
  File "assigning-shapefile.py", line 68, in <module>
    w.record(*tuple([row[f] for f in headers]))
  File "/usr/local/lib/python3.5/dist-packages/shapefile.py", line 1040, in record
    record = [recordList[i] for i in range(fieldCount)]
  File "/usr/local/lib/python3.5/dist-packages/shapefile.py", line 1040, in <listcomp>
    record = [recordList[i] for i in range(fieldCount)]
IndexError: tuple index out of range

而且，如果我们查看 shapefile 内部，我们会看到类似这样的内容：

QGIS attribute table before and after the code execution

我得出的结论是字段已成功添加，但行（w.record 指定了字段名称）没有。

Answer 1

使用 osgeo 库使用非常简单的方法解决了问题：

# --
# USAGE: 
#       python3 assinging-shapefile.py [input-shapefile] [output-shapefile]
# --
# REQUISITE: 
#   The classification csv file should be edited as a header of classifiers and its labels. The file name is mandatory to be IMAGE_NAME-classified.csv
#   Ex: 
#       Filename: IMAGE_NAME-classified.csv
#       Content: 
#               Random forest, Multilayer-Perc, CRF, SVM
#               vegetation, vegetation, building, vegetation
#               wall, window, window, window 
#               ...
# --

import os, sys
import shapefile, csv

from os.path import basename
from osgeo import ogr

filename_full = sys.argv[1]
output_full = sys.argv[2]

name, file_extension = os.path.splitext(filename_full)
output_name, file_extension = os.path.splitext(output_full)

filename_dbf =  name + ".dbf"
filename_classified =  name + "_classified.csv"
output_dbf =  output_name + ".dbf"

myshp = open(filename_full, "rb")
mydbf = open(filename_dbf, "rb")
r = shapefile.Reader(shp=myshp, dbf=mydbf)
w = shapefile.Writer(r.shapeType)

# copy shapefile
w._shapes.extend(r.shapes())
w.records.extend(r.records())
w.fields = list(r.fields)
w.save(output_full)

# read the csv records
csvRecords = []
csvHeaders = []
with open(filename_classified, 'rt', encoding='utf-8') as csvfile:
    reader = csv.DictReader(csvfile, delimiter=',')
    csvHeaders = reader.fieldnames  
    for line in reader:
        csvRecords.append(line)

driver = ogr.GetDriverByName('ESRI Shapefile')
infile = driver.Open(output_full, 1)

for classifier in csvHeaders:
    field = ogr.FieldDefn(classifier, ogr.OFTString)
    field.SetWidth(16)

    layer = infile.GetLayer()
    layer.CreateField(field)

cont = 0
for feature in layer:   
    for classifier in csvHeaders:       
        if(feature.GetField(0)!=cont):
            cont += 1

        feature.SetField(classifier, csvRecords[cont][classifier]) 
        layer.SetFeature(feature)           
infile=None

它能够 (i) 读取 csv 文件（包含要添加的列），(ii) 读取 shapefile 并复制它，(iii) 通过用对应的行编辑每一行来修改 .shp 副本csv 记录。

Pyshp 将新字段附加到现有 shapefile 但不记录值

Pyshp appends new fields but not record values to an existing shapefile

python

csv

shapefile