data = {
"Duration":{
"0":60,
"1":60,
"2":60,
"3":45,
"4":45,
"5":60
},
"Pulse":{
"0":110,
"1":117,
"2":103,
"3":109,
"4":117,
"5":102
},
"Maxpulse":{
"0":130,
"1":145,
"2":135,
"3":175,
"4":148,
"5":127
},
"Calories":{
"0":409,
"1":479,
"2":340,
"3":282,
"4":406,
"5":300
}
}
df = pd.DataFrame(data)
print(df) 
head/tail:
print(df.info()):
# dropna(): method returns a new DataFrame by default, and will not change the original.
# dropna(inplace = True) will NOT return a new DataFrame, but it will remove all rows containing NULL values from the original DataFrame.
print(df.dropna(inplace=False))