diff --git a/pmd_beamphysics/fields/fieldmesh.py b/pmd_beamphysics/fields/fieldmesh.py
index 78bea06..868b835 100644
--- a/pmd_beamphysics/fields/fieldmesh.py
+++ b/pmd_beamphysics/fields/fieldmesh.py
@@ -1,6 +1,6 @@
-from pmd_beamphysics.units import dimension, dimension_name, SI_symbol, pg_units
+from pmd_beamphysics.units import pg_units
 
-from pmd_beamphysics.readers import component_data, expected_record_unit_dimension, field_record_components, decode_attrs, field_paths, component_from_alias, load_field_attrs, component_alias
+from pmd_beamphysics.readers import component_data, expected_record_unit_dimension, field_record_components, field_paths, component_from_alias, load_field_attrs, component_alias
 
 from pmd_beamphysics.writers import write_pmd_field, pmd_field_init
 
@@ -11,7 +11,7 @@
 from pmd_beamphysics.interfaces.ansys import read_ansys_ascii_3d_fields
 from pmd_beamphysics.interfaces.astra import write_astra_1d_fieldmap, read_astra_3d_fieldmaps, write_astra_3d_fieldmaps, astra_1d_fieldmap_data
 from pmd_beamphysics.interfaces.gpt import write_gpt_fieldmesh
-from pmd_beamphysics.interfaces.impact import create_impact_solrf_fieldmap_fourier, create_impact_solrf_ele
+from pmd_beamphysics.interfaces.impact import create_impact_solrf_ele
 from pmd_beamphysics.interfaces.superfish import write_superfish_t7, read_superfish_t7
 
 from pmd_beamphysics.fields.expansion import expand_fieldmesh_from_onaxis
@@ -23,7 +23,6 @@
 import numpy as np
 from copy import deepcopy
 import os
-import functools
 
 
 c_light = 299792458.
@@ -446,7 +445,7 @@ def from_ansys_ascii_3d(cls, *,
         """
         
         if frequency is None:
-            raise ValueError(f"Please provide a frequency")
+            raise ValueError("Please provide a frequency")
         
         data = read_ansys_ascii_3d_fields(efile, hfile, frequency=frequency)
         return cls(data=data)
diff --git a/pmd_beamphysics/interfaces/lucretia.py b/pmd_beamphysics/interfaces/lucretia.py
index e7bdcc4..4e8ceca 100644
--- a/pmd_beamphysics/interfaces/lucretia.py
+++ b/pmd_beamphysics/interfaces/lucretia.py
@@ -67,7 +67,7 @@ def lucretia_to_data(filename, ele_name='BEGINNING', t_ref=0, exclude_dead_parti
     elif (len(ele_list) == 1):
         ele_name = ele_list[0]
         
-    mdat = sio.loadmat(filename);
+    mdat = sio.loadmat(filename)
     
     coords = mdat['bstore'][ele_name][0,0]['Bunch'][0,0]['x'][0,0]
     charges = mdat['bstore'][ele_name][0,0]['Bunch'][0,0]['Q'][0,0][0]
diff --git a/pmd_beamphysics/labels.py b/pmd_beamphysics/labels.py
index 7d2c896..e2e7fff 100644
--- a/pmd_beamphysics/labels.py
+++ b/pmd_beamphysics/labels.py
@@ -1,4 +1,4 @@
-from pmd_beamphysics.units import pg_units, parse_bunching_str, nice_array
+from pmd_beamphysics.units import parse_bunching_str, nice_array
 
 
 TEXLABEL = {
@@ -36,20 +36,20 @@
  'gamma': r'\gamma',
  'theta': r'\theta',
  'charge': 'Q',
- 'twiss_alpha_x'     : 'Twiss\ '+r'\alpha_x',
- 'twiss_beta_x'      : 'Twiss\ '+r'\beta_x',   
- 'twiss_gamma_x'     : 'Twiss\ '+r'\gamma_x',   
- 'twiss_eta_x'       : 'Twiss\ '+r'\eta_x',   
- 'twiss_etap_x'      : 'Twiss\ '+r"\eta'_x",     
- 'twiss_emit_x'      : 'Twiss\ '+r'\epsilon_{x}',
- 'twiss_norm_emit_x' : 'Twiss\ '+r'\epsilon_{n, x}',
- 'twiss_alpha_y'     : 'Twiss\ '+r'\alpha_y',
- 'twiss_beta_y'      : 'Twiss\ '+r'\beta_y',   
- 'twiss_gamma_y'     : 'Twiss\ '+r'\gamma_y',   
- 'twiss_eta_y'       : 'Twiss\ '+r'\eta_y',   
- 'twiss_etap_y'      : 'Twiss\ '+r"\eta'_y",     
- 'twiss_emit_y'      : 'Twiss\ '+r'\epsilon_{y}',
- 'twiss_norm_emit_y' : 'Twiss\ '+r'\epsilon_{n, y}',    
+ 'twiss_alpha_x'     : r'Twiss\ '+r'\alpha_x',
+ 'twiss_beta_x'      : r'Twiss\ '+r'\beta_x',   
+ 'twiss_gamma_x'     : r'Twiss\ '+r'\gamma_x',   
+ 'twiss_eta_x'       : r'Twiss\ '+r'\eta_x',   
+ 'twiss_etap_x'      : r'Twiss\ '+r"\eta'_x",     
+ 'twiss_emit_x'      : r'Twiss\ '+r'\epsilon_{x}',
+ 'twiss_norm_emit_x' : r'Twiss\ '+r'\epsilon_{n, x}',
+ 'twiss_alpha_y'     : r'Twiss\ '+r'\alpha_y',
+ 'twiss_beta_y'      : r'Twiss\ '+r'\beta_y',   
+ 'twiss_gamma_y'     : r'Twiss\ '+r'\gamma_y',   
+ 'twiss_eta_y'       : r'Twiss\ '+r'\eta_y',   
+ 'twiss_etap_y'      : r'Twiss\ '+r"\eta'_y",     
+ 'twiss_emit_y'      : r'Twiss\ '+r'\epsilon_{y}',
+ 'twiss_norm_emit_y' : r'Twiss\ '+r'\epsilon_{n, y}',    
 # 'species_charge',
 # 'weight',
  'average_current': r'I_{av}',
@@ -122,7 +122,7 @@ def texlabel(key: str):
     if key.startswith('bunching'):
         wavelength = parse_bunching_str(key)
         x, _, prefix = nice_array(wavelength)
-        return f'\mathrm{{bunching~at}}~{x:.1f}~\mathrm{{ {prefix}m }}'
+        return fr'\mathrm{{bunching~at}}~{x:.1f}~\mathrm{{ {prefix}m }}'
     
     return None
     
diff --git a/pmd_beamphysics/readers.py b/pmd_beamphysics/readers.py
index 7b63e14..4efdaf8 100644
--- a/pmd_beamphysics/readers.py
+++ b/pmd_beamphysics/readers.py
@@ -1,8 +1,7 @@
-from .units import dimension, dimension_name, SI_symbol, pg_units, c_light, e_charge
+from .units import dimension, dimension_name, SI_symbol, c_light, e_charge
 from .tools import decode_attrs, decode_attr
 
 
-import h5py
 import numpy as np
 
 #-----------------------------------------
diff --git a/pmd_beamphysics/writers.py b/pmd_beamphysics/writers.py
index 0a153b6..6abc8de 100644
--- a/pmd_beamphysics/writers.py
+++ b/pmd_beamphysics/writers.py
@@ -1,6 +1,6 @@
 import numpy as np
 
-from .units import unit, pg_units
+from .units import pg_units
 from .readers import component_from_alias, load_field_attrs
 from .tools import fstr, encode_attrs
 
diff --git a/setup.py b/setup.py
index 49a2c4d..36e2ce7 100644
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,6 @@
 import versioneer
 from setuptools import setup, find_packages
-from os import path, environ
+from os import path
 
 cur_dir = path.abspath(path.dirname(__file__))