Move import commands to the script part

The corresponding modules are not used in the functions.

Inst_eddies/Analysis/plot_eddy_contours.py

@@ -20,10 +20,7 @@ import shapefile
 import numpy as np
 from cartopy.mpl import geoaxes
 import cartopy.crs as ccrs
-from os import path
 from matplotlib import patches
-import f90nml
-import sys
 import util_eddies
 
 def select_ishapes(d: int, SHPC: util_eddies.SHPC_class, i_slice: int,
@@ -159,6 +156,9 @@ def plot_grid_points(grid_nml, window, ax, src_crs):
 if __name__ == "__main__":
     import matplotlib.pyplot as plt
     import argparse
+    import f90nml
+    from os import path
+    import sys
 
     parser = argparse.ArgumentParser()
     parser.add_argument("-d", "--date", type = int, help = "date index")