如何将特定位置的 netCDF 提取为 csv

Question

我想将特定位置的时间序列从 NetCDF 提取到 csv。我用代码走到了这一步，但它给出了 TypeError：需要一个类似字节的对象，而不是"str">

如何克服此问题？另外，这个开发的代码是否会有输出：特定位置的时间/mwp？

import netCDF4 
import pandas as pd
import matplotlib.pyplot as plt
import csv
import numpy as np
from netCDF4 import Dataset, num2date
from pylab import *
import xarray
f = netCDF4.Dataset('Wave_period_global.nc')
f.variables.keys()
print (f)
lat = f.variables['latitude'][:]
lon = f.variables['longitude'][:]
time_var = f.variables['time']
dtime = netCDF4.num2date(time_var[:],time_var.units)
mwp = f.variables['mwp'][:]
print(lon.min(), lon.max())
print(lat.min(), lat.max())
longitude = 172
latitude = 50
def near(array,value):
    idx=(abs(array-value)).argmin()
    return idx
ix = near(lat, latitude)
iy = near(lon, longitude)
print ('Latitude =',ix)
print ('Longitude =',iy)
with open ('Wave_period_global.csv', 'wb') as csvfile:
    filewriter = csv.writer(csvfile, delimiter=',',
                            quotechar='|', quoting=csv.QUOTE_MINIMAL)
    for ln in range(len(lon)):
        for lt in range(len(lat)):
            value=f.variables['mwp'][0][lt][ln]
            dtime = netCDF4.num2date(time_var[0],time_var.units)
            print(dtime,lat[lt],lon[ln,],value)
            filewriter.writerow([dtime,lat[lt],lon[ln,],value])

Answer 1

请参阅我上面的评论。我将输出作为 csv 保留在我的答案之外，以专注于您的真正问题。

from netCDF4 import Dataset, num2date
f = netCDF4.Dataset('Wave_period_global.nc')
lat = f.variables['latitude'][:]
lon = f.variables['longitude'][:]
time_var = f.variables['time']
# These are all datetime object.
dtime = netCDF4.num2date(time_var[:],time_var.units)
mwp = f.variables['mwp'][:]
print(lon.min(), lon.max())
print(lat.min(), lat.max())
longitude = 172
latitude = 50
def near(array,value):
    idx=(abs(array-value)).argmin()
    return idx
ix = near(lat, latitude)
iy = near(lon, longitude)
print ('Latitude =',ix)
print ('lat[] =', lat[ix])
print ('Longitude =',iy)
print ('lon[] =', lon[iy])
for i in range(len(dtime)):
  value=f.variables['mwp'][i][ix][iy]
  print(dtime[i],lat[ix],lon[iy,],value)