Upgrade to Python 3.8 syntax (#159)

* upgrade to python 3.8+ syntax

* remove six dependency

* upgrade notebooks to Python 3.8+ syntax

* add news fragment

[skip ci]

Author: mcflugen

news/159.misc

@@ -0,0 +1,3 @@
+Removed dependency on ``six`` since we don't support Python 2 and updated code
+to use Python 3.8+ syntax.
+

notebooks/cem.ipynb

@@ -275,7 +275,7 @@
     "cem.get_grid_spacing(grid_id, out=spacing)\n",
     "\n",
     "print('The grid has %d rows and %d columns' % (shape[0], shape[1]))\n",
-    "print('The spacing between rows is %f m and between columns is %f m' % (spacing[0], spacing[1]))"
+    "print('The spacing between rows is {:f} m and between columns is {:f} m'.format(spacing[0], spacing[1]))"
    ]
   },
   {
@@ -399,7 +399,7 @@
     "# read in the csv file of bedload measurements in the Rhine River, the Netherlands\n",
     "# these data were collected over different days over a season in 2004, at nearby locations.\n",
     "# plot how river discharge controls bedload; Q (x-axis) and Qb (y-axis) data. \n",
-    "# label both axes\n"
+    "# label both axes"
    ]
   },
   {
@@ -425,7 +425,7 @@
    "outputs": [],
    "source": [
     "# extrapolate this relationship and calculate how much river discharge, Q, \n",
-    "# would be needed to transport the model specification Qb of 1250 kg/s\n"
+    "# would be needed to transport the model specification Qb of 1250 kg/s"
    ]
   },
   {

notebooks/child.ipynb

@@ -23,8 +23,6 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from __future__ import print_function\n",
-    "\n",
     "# Some magic to make plots appear within the notebook\n",
     "%matplotlib inline\n",
     "\n",

notebooks/hydrotrend.ipynb

@@ -60,7 +60,7 @@
    "source": [
     "# To start, import numpy and matplotlib.\n",
     "import matplotlib.pyplot as plt\n",
-    "import numpy as np\n"
+    "import numpy as np"
    ]
   },
   {
@@ -237,8 +237,7 @@
     "# compare with the last year\n",
     "plt.plot(q[-366:-1],'grey')\n",
     "plt.title('HydroTrend simulation of first and last year discharge, Waiapaoa River')\n",
-    "plt.show()\n",
-    "\n"
+    "plt.show()"
    ]
   },
   {
@@ -269,7 +268,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# your code goes here\n"
+    "# your code goes here"
    ]
   },
   {
@@ -288,7 +287,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# here you can calculate the maximum river discharge.\n"
+    "# here you can calculate the maximum river discharge."
    ]
   },
   {
@@ -337,7 +336,7 @@
     "# your code goes here\n",
     "# you will have to sum all days of the individual years, to get the annual loads, then calculate the mean over the 100 years.\n",
     "# one possible trick is to use the .reshape() method\n",
-    "# plot a graph of the 100 years timeseries of the total annual loads \n"
+    "# plot a graph of the 100 years timeseries of the total annual loads "
    ]
   },
   {
@@ -346,7 +345,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# take the mean over the 100 years\n"
+    "# take the mean over the 100 years"
    ]
   },
   {
@@ -430,8 +429,7 @@
     "# your code that prints out the mean river discharge, the mean sediment load and the mean bedload goes here\n",
     "\n",
     "\n",
-    "# print out these same parameters for the basecase for comparison\n",
-    "\n"
+    "# print out these same parameters for the basecase for comparison"
    ]
   },
   {

notebooks/hydrotrend_Ganges.ipynb

@@ -306,7 +306,7 @@
     "z = np.polyfit(q_y_vals.flatten(), q_mean_rows_GQ0.flatten(), 1)\n",
     "p = np.poly1d(z)\n",
     "plt.plot(q_y_vals, p(q_y_vals), \"r--\")\n",
-    "plt.suptitle(\"y=%.6fx+%.6f\" % (z[0], z[1]), y=0.8)\n",
+    "plt.suptitle(\"y={:.6f}x+{:.6f}\".format(z[0], z[1]), y=0.8)\n",
     "plt.show()"
    ]
   },
@@ -359,7 +359,7 @@
     "z = np.polyfit(qs_y_vals.flatten(), qs_mean_rows_GQ0.flatten(), 1)\n",
     "p = np.poly1d(z)\n",
     "plt.plot(qs_y_vals, p(qs_y_vals), \"r--\")\n",
-    "plt.suptitle(\"y=%.6fx+%.6f\" % (z[0], z[1]), y=0.85)\n",
+    "plt.suptitle(\"y={:.6f}x+{:.6f}\".format(z[0], z[1]), y=0.85)\n",
     "plt.show()"
    ]
   },
@@ -394,29 +394,29 @@
    "outputs": [],
    "source": [
     "print(\n",
-    "    \"Mean Water Discharge = {0} {1}\".format(\n",
+    "    \"Mean Water Discharge = {} {}\".format(\n",
     "        q_GQ0.mean(),\n",
     "        hydrotrend_GQ0.get_var_units(\"channel_exit_water__volume_flow_rate\"),\n",
     "    )\n",
     ")\n",
     "print(\n",
-    "    \"Mean Bedload Discharge = {0} {1}\".format(\n",
+    "    \"Mean Bedload Discharge = {} {}\".format(\n",
     "        qb_GQ0.mean(),\n",
     "        hydrotrend_GQ0.get_var_units(\n",
     "            \"channel_exit_water_sediment~bedload__mass_flow_rate\"\n",
     "        ),\n",
     "    )\n",
     ")\n",
     "print(\n",
-    "    \"Mean Suspended Sediment Discharge = {0} {1}\".format(\n",
+    "    \"Mean Suspended Sediment Discharge = {} {}\".format(\n",
     "        qs_GQ0.mean(),\n",
     "        hydrotrend_GQ0.get_var_units(\n",
     "            \"channel_exit_water_sediment~suspended__mass_flow_rate\"\n",
     "        ),\n",
     "    )\n",
     ")\n",
     "print(\n",
-    "    \"Mean Suspended Sediment Concentration = {0} {1}\".format(\n",
+    "    \"Mean Suspended Sediment Concentration = {} {}\".format(\n",
     "        cs_GQ0.mean(),\n",
     "        hydrotrend_GQ0.get_var_units(\n",
     "            \"channel_exit_water_sediment~suspended__mass_concentration\"\n",

notebooks/sedflux3d.ipynb

@@ -23,8 +23,6 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from __future__ import print_function\n",
-    "\n",
     "# Some magic to make plots appear within the notebook\n",
     "%matplotlib inline\n",
     "\n",

notebooks/subside.ipynb

@@ -43,8 +43,6 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from __future__ import print_function\n",
-    "\n",
     "%matplotlib inline\n",
     "\n",
     "import matplotlib.pyplot as plt"

pymt/cmd/cmt_config.py

@@ -3,7 +3,6 @@
 import socket
 import sys
 
-import six
 import yaml
 from model_metadata.find import find_model_data_files
 
@@ -17,19 +16,19 @@ def __init__(self, stdout=None, stderr=None):
         self._err = stderr or sys.stderr
 
     def __enter__(self):
-        if isinstance(self._out, six.string_types):
+        if isinstance(self._out, str):
             sys.stdout = open(self._out, "w")
         else:
             sys.stdout = self._out
-        if isinstance(self._err, six.string_types):
+        if isinstance(self._err, str):
             sys.stderr = open(self._err, "w")
         else:
             sys.stderr = self._err
 
     def __exit__(self, type_, value, traceback):
-        if isinstance(self._out, six.string_types):
+        if isinstance(self._out, str):
             sys.stdout.close()
-        if isinstance(self._err, six.string_types):
+        if isinstance(self._err, str):
             sys.stderr.close()
 
         sys.stdout = self._stdout

pymt/component/component.py

@@ -57,7 +57,6 @@
 """
 import warnings
 
-import six
 import yaml
 
 from ..events.chain import ChainEvent
@@ -146,7 +145,7 @@ def __init__(
         if provides is None:
             provides = set()
 
-        if isinstance(port, six.string_types):
+        if isinstance(port, str):
             if name is None:
                 name = port
             self._port = services.instantiate_component(port, name)
@@ -419,7 +418,7 @@ def from_path(cls, path):
         Component
             A newly-created component.
         """
-        with open(path, "r") as yaml_file:
+        with open(path) as yaml_file:
             return cls._from_yaml(yaml_file.read())
 
     @classmethod

pymt/component/model.py

@@ -1,6 +1,5 @@
 import os
 
-import six
 import yaml
 
 from .component import Component
@@ -30,7 +29,7 @@ def get_exchange_item_mapping(items):
     """
     mapping = []
     for item in items:
-        if isinstance(item, six.string_types):
+        if isinstance(item, str):
             item_map = (item, item)
         else:
             try:
@@ -83,7 +82,7 @@ def duration(self, duration):
     def go(self, filename=None):
         """Start the model."""
         if filename:
-            with open(filename, "r") as f:
+            with open(filename) as f:
                 model = yaml.safe_load(f.read())
             self._driver, self._duration = (model["driver"], model["duration"])
 
@@ -158,7 +157,7 @@ def from_file(cls, filename):
         model : Model
             A newly-created model.
         """
-        with open(filename, "r") as fp:
+        with open(filename) as fp:
             return cls.load(fp)
 
     @classmethod