removing below 0 from cases

graphs.py

@@ -43,6 +43,7 @@ def draw_daily_county_state_cases_graph(df, co, state):
     cases_by_day = df.groupby("date")["cases"].sum().reset_index(name="cases")
     shifted = cases_by_day["cases"].shift(1)
     cases_by_day["daily_cases"] = cases_by_day["cases"] - shifted
+    cases_by_day.loc[cases_by_day.daily_cases < 0, "daily_cases"] = 0
     cases_by_day.drop(columns=["cases"], axis=1, inplace=True)
     cases_by_day.set_index("date", inplace=True)
     st.write(f"Daily cases({co}, {state}):")