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Put updated info under existing subheads instead of tagged onto the end where it might be missed
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pjz
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Creating an empty dictionary

Creating an empty dictionary

Creating a dictionary with initial values

Creating a dictionary with initial values

Inserting/Updating a single value

Inserting/Updating a single value

Inserting/Updating multiple values

Inserting/Updating multiple values

Creating a merged dictionary without modifying originalsPython 3.9+:

The update operator|= now works for dictionaries:

data |= {'c':3,'d':4}

Creating a merged dictionary without modifying originals

data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2

Deleting items in dictionaryPython 3.5+:

This uses a new feature called dictionary unpacking.

data = {**data1, **data2, **data3}

Python 3.9+:

The merge operator| now works for dictionaries:

data = data1 | {'c':3,'d':4}

Deleting items in dictionary

Check if a key is already in dictionary

Check if a key is already in dictionary

Iterate through pairs in a dictionary

Iterate through pairs in a dictionary

Create a dictionary from two lists

Create a dictionary from two lists

New to Python 3.5

Creating a merged dictionary without modifying originals:

This uses a new feature called dictionary unpacking.

data = {**data1, **data2, **data3}

New to Python 3.9

Update or add values for an existing dictionary

The update operator|= now works for dictionaries:

data |= {'c':3,'d':4}

Creating a merged dictionary without modifying originals

The merge operator| now works for dictionaries:

data = data1 | {'c':3,'d':4}

Feel free to add more!

Creating an empty dictionary

Creating a dictionary with initial values

Inserting/Updating a single value

Inserting/Updating multiple values

Creating a merged dictionary without modifying originals

data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2

Deleting items in dictionary

Check if a key is already in dictionary

Iterate through pairs in a dictionary

Create a dictionary from two lists

New to Python 3.5

Creating a merged dictionary without modifying originals:

This uses a new feature called dictionary unpacking.

data = {**data1, **data2, **data3}

New to Python 3.9

Update or add values for an existing dictionary

The update operator|= now works for dictionaries:

data |= {'c':3,'d':4}

Creating a merged dictionary without modifying originals

The merge operator| now works for dictionaries:

data = data1 | {'c':3,'d':4}

Feel free to add more!

Creating an empty dictionary

Creating a dictionary with initial values

Inserting/Updating a single value

Inserting/Updating multiple values

Python 3.9+:

The update operator|= now works for dictionaries:

data |= {'c':3,'d':4}

Creating a merged dictionary without modifying originals

data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2

Python 3.5+:

This uses a new feature called dictionary unpacking.

data = {**data1, **data2, **data3}

Python 3.9+:

The merge operator| now works for dictionaries:

data = data1 | {'c':3,'d':4}

Deleting items in dictionary

Check if a key is already in dictionary

Iterate through pairs in a dictionary

Create a dictionary from two lists

fix typo
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pjz
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  • 60

I feel like consolidating info about Python dictionaries:

Creating an empty dictionary

data = {}
# OR
data = dict()

Creating a dictionary with initial values

data = {'a': 1, 'b': 2, 'c': 3}
# OR
data = dict(a=1, b=2, c=3)
# OR
data = {k: v for k, v in (('a', 1), ('b',2), ('c',3))}

Inserting/Updating a single value

data['a'] = 1 # Updates if 'a' exists, else adds 'a'
# OR
data.update({'a': 1})
# OR
data.update(dict(a=1))
# OR
data.update(a=1)

Inserting/Updating multiple values

data.update({'c':3,'d':4}) # Updates 'c' and adds 'd'

Creating a merged dictionary without modifying originals

data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2

Deleting items in dictionary

del data[key] # Removes specific element in a dictionary
data.pop(key) # Removes the key & returns the value
data.clear() # Clears entire dictionary

Check if a key is already in dictionary

key in data

Iterate through pairs in a dictionary

for key in data: # Iterates just through the keys, ignoring the values
for key, value in d.items(): # Iterates through the pairs
for key in d.keys(): # Iterates just through key, ignoring the values
for value in d.values(): # Iterates just through value, ignoring the keys

Create a dictionary from two lists

data = dict(zip(list_with_keys, list_with_values))

New to Python 3.5

Creating a merged dictionary without modifying originals:

This uses a new featruefeature called dictionary unpacking.

data = {**data1, **data2, **data3}

New to Python 3.9

Update or add values for an existing dictionary

The update operator |= now works for dictionaries:

data |= {'c':3,'d':4}

Creating a merged dictionary without modifying originals

The merge operator | now works for dictionaries:

data = data1 | {'c':3,'d':4}

Feel free to add more!

I feel like consolidating info about Python dictionaries:

Creating an empty dictionary

data = {}
# OR
data = dict()

Creating a dictionary with initial values

data = {'a': 1, 'b': 2, 'c': 3}
# OR
data = dict(a=1, b=2, c=3)
# OR
data = {k: v for k, v in (('a', 1), ('b',2), ('c',3))}

Inserting/Updating a single value

data['a'] = 1 # Updates if 'a' exists, else adds 'a'
# OR
data.update({'a': 1})
# OR
data.update(dict(a=1))
# OR
data.update(a=1)

Inserting/Updating multiple values

data.update({'c':3,'d':4}) # Updates 'c' and adds 'd'

Creating a merged dictionary without modifying originals

data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2

Deleting items in dictionary

del data[key] # Removes specific element in a dictionary
data.pop(key) # Removes the key & returns the value
data.clear() # Clears entire dictionary

Check if a key is already in dictionary

key in data

Iterate through pairs in a dictionary

for key in data: # Iterates just through the keys, ignoring the values
for key, value in d.items(): # Iterates through the pairs
for key in d.keys(): # Iterates just through key, ignoring the values
for value in d.values(): # Iterates just through value, ignoring the keys

Create a dictionary from two lists

data = dict(zip(list_with_keys, list_with_values))

New to Python 3.5

Creating a merged dictionary without modifying originals:

This uses a new featrue called dictionary unpacking.

data = {**data1, **data2, **data3}

New to Python 3.9

Update or add values for an existing dictionary

The update operator |= now works for dictionaries:

data |= {'c':3,'d':4}

Creating a merged dictionary without modifying originals

The merge operator | now works for dictionaries:

data = data1 | {'c':3,'d':4}

Feel free to add more!

I feel like consolidating info about Python dictionaries:

Creating an empty dictionary

data = {}
# OR
data = dict()

Creating a dictionary with initial values

data = {'a': 1, 'b': 2, 'c': 3}
# OR
data = dict(a=1, b=2, c=3)
# OR
data = {k: v for k, v in (('a', 1), ('b',2), ('c',3))}

Inserting/Updating a single value

data['a'] = 1 # Updates if 'a' exists, else adds 'a'
# OR
data.update({'a': 1})
# OR
data.update(dict(a=1))
# OR
data.update(a=1)

Inserting/Updating multiple values

data.update({'c':3,'d':4}) # Updates 'c' and adds 'd'

Creating a merged dictionary without modifying originals

data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2

Deleting items in dictionary

del data[key] # Removes specific element in a dictionary
data.pop(key) # Removes the key & returns the value
data.clear() # Clears entire dictionary

Check if a key is already in dictionary

key in data

Iterate through pairs in a dictionary

for key in data: # Iterates just through the keys, ignoring the values
for key, value in d.items(): # Iterates through the pairs
for key in d.keys(): # Iterates just through key, ignoring the values
for value in d.values(): # Iterates just through value, ignoring the keys

Create a dictionary from two lists

data = dict(zip(list_with_keys, list_with_values))

New to Python 3.5

Creating a merged dictionary without modifying originals:

This uses a new feature called dictionary unpacking.

data = {**data1, **data2, **data3}

New to Python 3.9

Update or add values for an existing dictionary

The update operator |= now works for dictionaries:

data |= {'c':3,'d':4}

Creating a merged dictionary without modifying originals

The merge operator | now works for dictionaries:

data = data1 | {'c':3,'d':4}

Feel free to add more!

Use better values for Python 3.9 examokes
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Rotareti
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I feel like consolidating info about Python dictionaries:

Creating an empty dictionary

data = {}
# OR
data = dict()

Creating a dictionary with initial values

data = {'a': 1, 'b': 2, 'c': 3}
# OR
data = dict(a=1, b=2, c=3)
# OR
data = {k: v for k, v in (('a', 1), ('b',2), ('c',3))}

Inserting/Updating a single value

data['a'] = 1 # Updates if 'a' exists, else adds 'a'
# OR
data.update({'a': 1})
# OR
data.update(dict(a=1))
# OR
data.update(a=1)

Inserting/Updating multiple values

data.update({'c':3,'d':4}) # Updates 'c' and adds 'd'

Creating a merged dictionary without modifying originals

data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2

Deleting items in dictionary

del data[key] # Removes specific element in a dictionary
data.pop(key) # Removes the key & returns the value
data.clear() # Clears entire dictionary

Check if a key is already in dictionary

key in data

Iterate through pairs in a dictionary

for key in data: # Iterates just through the keys, ignoring the values
for key, value in d.items(): # Iterates through the pairs
for key in d.keys(): # Iterates just through key, ignoring the values
for value in d.values(): # Iterates just through value, ignoring the keys

Create a dictionary from two lists

data = dict(zip(list_with_keys, list_with_values))

New to Python 3.5

Creating a merged dictionary without modifying originals:

This uses a new featrue called dictionary unpacking.

data = {**data1, **data2, **data3}

New to Python 3.9

Update or add values for an existing dictionary

The update operator|= now works for dictionaries:

data |= {'c':3,'d':4}

Creating a merged dictionary without modifying originals

The merge operator| now works for dictionaries:

data = data1 | {'c':3,'d':4}

Feel free to add more!

I feel like consolidating info about Python dictionaries:

Creating an empty dictionary

data = {}
# OR
data = dict()

Creating a dictionary with initial values

data = {'a': 1, 'b': 2, 'c': 3}
# OR
data = dict(a=1, b=2, c=3)
# OR
data = {k: v for k, v in (('a', 1), ('b',2), ('c',3))}

Inserting/Updating a single value

data['a'] = 1 # Updates if 'a' exists, else adds 'a'
# OR
data.update({'a': 1})
# OR
data.update(dict(a=1))
# OR
data.update(a=1)

Inserting/Updating multiple values

data.update({'c':3,'d':4}) # Updates 'c' and adds 'd'

Creating a merged dictionary without modifying originals

data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2

Deleting items in dictionary

del data[key] # Removes specific element in a dictionary
data.pop(key) # Removes the key & returns the value
data.clear() # Clears entire dictionary

Check if a key is already in dictionary

key in data

Iterate through pairs in a dictionary

for key in data: # Iterates just through the keys, ignoring the values
for key, value in d.items(): # Iterates through the pairs
for key in d.keys(): # Iterates just through key, ignoring the values
for value in d.values(): # Iterates just through value, ignoring the keys

Create a dictionary from two lists

data = dict(zip(list_with_keys, list_with_values))

New to Python 3

Creating a merged dictionary without modifying originals

data = {**data1, **data2, **data3}

Feel free to add more!

I feel like consolidating info about Python dictionaries:

Creating an empty dictionary

data = {}
# OR
data = dict()

Creating a dictionary with initial values

data = {'a': 1, 'b': 2, 'c': 3}
# OR
data = dict(a=1, b=2, c=3)
# OR
data = {k: v for k, v in (('a', 1), ('b',2), ('c',3))}

Inserting/Updating a single value

data['a'] = 1 # Updates if 'a' exists, else adds 'a'
# OR
data.update({'a': 1})
# OR
data.update(dict(a=1))
# OR
data.update(a=1)

Inserting/Updating multiple values

data.update({'c':3,'d':4}) # Updates 'c' and adds 'd'

Creating a merged dictionary without modifying originals

data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2

Deleting items in dictionary

del data[key] # Removes specific element in a dictionary
data.pop(key) # Removes the key & returns the value
data.clear() # Clears entire dictionary

Check if a key is already in dictionary

key in data

Iterate through pairs in a dictionary

for key in data: # Iterates just through the keys, ignoring the values
for key, value in d.items(): # Iterates through the pairs
for key in d.keys(): # Iterates just through key, ignoring the values
for value in d.values(): # Iterates just through value, ignoring the keys

Create a dictionary from two lists

data = dict(zip(list_with_keys, list_with_values))

New to Python 3.5

Creating a merged dictionary without modifying originals:

This uses a new featrue called dictionary unpacking.

data = {**data1, **data2, **data3}

New to Python 3.9

Update or add values for an existing dictionary

The update operator|= now works for dictionaries:

data |= {'c':3,'d':4}

Creating a merged dictionary without modifying originals

The merge operator| now works for dictionaries:

data = data1 | {'c':3,'d':4}

Feel free to add more!

Active reading [<https://en.wikipedia.org/wiki/History_of_Python#Version_3>]. Used more standard formatting.
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Peter Mortensen
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New Python3 options
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Yugal Jindle
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Added new formatting to iterate through keys in values in a dictionary.
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Remco Haszing
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Added new formatting to iterate through keys in values in a dictionary.
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Split massive code block to avoid the need to scroll inside this answer.
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Shadow
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Added dict comprehensions, which didn't exist when this answer was written.
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nmichaels
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Added "Creating a merged dictionary", other edits, comments, etc.
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jkdev
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Added "Creating a merged dictionary", other edits, comments, etc.
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jkdev
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added 47 characters in body
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Yugal Jindle
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Added additional information about dictionaries
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removed wrong statement, improved code block
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Marco Bonelli
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added 72 characters in body
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Marcin
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Yugal Jindle
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lang-py

AltStyle によって変換されたページ (->オリジナル) /