How to smoothen graphs with python

I am trying to smoothen this plot. But I was unable to do it. Tried to interpolate using splrep but its not working. Any help would be highly appreciated. The graph has been plotted by using Dataframe columns of Current, voltage and Operating hours.

df2=data[:2000]
plt.subplot(2,1,1)
plt.plot(df2['Op_Hours_Fcpm'],df2['Current'],'r')
plt.xlabel('Operating hours')
plt.title('Current Fluctuations')

plt.subplot(2,1,2)
plt.plot(df2['Op_Hours_Fcpm'],df2['Voltage'],'y')
plt.xlabel('Operating hours')
plt.title('Voltage Fluctuations')

plt.tight_layout()
plt.show()

I did try by another way as well:

fig, ax = plt.subplots()
ax.plot(x_int, current_int, lw = 5, alpha = 0.30, label = 'current')
ax.plot(x_int, voltage_int, lw = 5, alpha = 0.30, label = 'voltage')

ax.set_xlabel('ripples')
ax.set_ylabel('hrs')
# Set the correct xticks
ax.set_xticks(x_map)
ax.set_xticklabels(x)
fig.legend(bbox_to_anchor=(0.7, 0.3), loc='upper left', ncol=1)
fig.show()

This has given this output