code: def plotAllSweeps(abfFile):
      
      r = io.AxonIO(filename=abfFile)
      bl = r.read_block(lazy=False, cascade=True)     
      print(abfFile+"\nplotting %d sweeps..."%len(bl.segments))
      plt.figure(figsize=(12,10))
      plt.title(abfFile)
      for sweep in range(len(bl.segments)):
          trace = bl.segments[sweep].analogsignals[0]
          plt.plot(trace.times-trace.times[0],trace.magnitude,alpha=.5)    
      plt.ylabel(trace.dimensionality)
      plt.xlabel("seconds")
      plt.show()
      plt.close()
docs: simple example how to load an ABF file and plot every sweep.