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>>> person = {'name': 'Rose', 'age': 33}
>>> 'name' in person.keys()
# True
>>> 'height' in person.keys()
# False
>>> 'skin' in person # You can omit keys()
# False
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val = dict.get(key , defVal) # defVal is a default value if key does not exist
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>>> d = {'1': 'one', '3': 'three', '2': 'two', '5': 'five', '4': 'four'}
>>> 'one' in d.values()
True
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dict = { "How":1,"you":2,"like":3,"this":4}
key = "this"
if key in dict.keys():
print("present")
print("value =",dict[key])
else:
print("Not present")
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# Example dictionary
my_dict = {"key1": "value1", "key2": "value2", "key3": "value3"}
# Method 1: Using `in` operator
if "key2" in my_dict:
print("Key 'key2' exists in dictionary.")
# Method 2: Using `get()` method
if my_dict.get("key2"):
print("Key 'key2' exists in dictionary.")
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# in tests for the existence of a key in a dict:
d = {"key1": 10, "key2": 23}
if "key1" in d:
print("this will execute")
if "nonexistent key" in d:
print("this will not")
# Use dict.get() to provide a default value when the key does not exist:
d = {}
for i in range(10):
d[i] = d.get(i, 0) + 1
# To provide a default value for every key, either use dict.setdefault() on each assignment:
d = {}
for i in range(10):
d[i] = d.setdefault(i, 0) + 1
# or use defaultdict from the collections module:
from collections import defaultdict
d = defaultdict(int)
for i in range(10):
d[i] += 1
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my_dict = {'name': 'John', 'age': 25, 'country': 'USA'}
# Method 1: Using the 'in' operator
if 'age' in my_dict:
print("Key 'age' exists in the dictionary.")
else:
print("Key 'age' does not exist in the dictionary.")
# Method 2: Using the 'get' method
if my_dict.get('country') is not None:
print("Key 'country' exists in the dictionary.")
else:
print("Key 'country' does not exist in the dictionary.")