How to check if a given key already exists in a Python dictionary?

You can use in operator in Python to check if a key or value exists in Python dictionary as shown in the below example –

dict = {"name": "debjeet", "age": 35}

## Check if a key exists
if "name" in dict:
  print(True)
else:
  print(False)

if "sex" in dict:
  print(True)
else:
  print(False)

## Check if a value exists
if "debjeet" in dict.values():
  print(True)
else:
  print(False)

if "chandrima" in dict.values():
  print(True)
else:
  print(False)

## Returns
## True
## False 
## True
## False

dict = {"name": "debjeet", "age": 35}

## Check if a key exists

if "name" in dict:

print(True)

else:

print(False)

if "sex" in dict:

print(True)

else:

print(False)

## Check if a value exists

if "debjeet" in dict.values():

print(True)

else:

print(False)

if "chandrima" in dict.values():

print(True)

else:

print(False)

## Returns

## True

## False

## True

## False

Tags: FAQ, Python