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KeyDrop

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KeyDrop[assoc,{key1,key2,…}]

yields an association from which elements with keys keyi have been dropped.

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KeyDrop[{assoc1,assoc2,…},keys]

gives a list of associations.

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KeyDrop[keys]

represents an operator form of KeyDrop that can be applied to an expression.

Details

  • KeyDrop preserves the original order of elements.
  • Any keyi that does not appear in assoc is ignored.
  • KeyDrop can be applied not only to Association objects, but also to lists of rules.
  • KeyDrop[keys][expr] is equivalent to KeyDrop[expr,keys].

Examples

Basic Examples  (7)Summary of the most common use cases

Delete entry with the specified key from association:

In[1]:=1
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https://wolfram.com/xid/0e7skx8c-md42i6
Out[1]=1

Delete entries, given a list of keys:

In[1]:=1
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https://wolfram.com/xid/0e7skx8c-d5nzem
Out[1]=1

Delete entries from several associations, given a list of keys:

In[1]:=1
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https://wolfram.com/xid/0e7skx8c-gack3o
Out[1]=1

Delete entries from a list of rules, given a key:

In[1]:=1
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https://wolfram.com/xid/0e7skx8c-b9bgp7
Out[1]=1

Delete entries from several lists:

In[1]:=1
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https://wolfram.com/xid/0e7skx8c-jvrevh
Out[1]=1

Delete from a mixed list of an association and a list of rules:

In[1]:=1
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https://wolfram.com/xid/0e7skx8c-giuscb
Out[1]=1

Use the operator form of KeyDrop:

In[1]:=1
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https://wolfram.com/xid/0e7skx8c-836t6x
Out[1]=1
Wolfram Research (2014), KeyDrop, Wolfram Language function, https://reference.wolfram.com/language/ref/KeyDrop.html.
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Wolfram Research (2014), KeyDrop, Wolfram Language function, https://reference.wolfram.com/language/ref/KeyDrop.html.

Text

Wolfram Research (2014), KeyDrop, Wolfram Language function, https://reference.wolfram.com/language/ref/KeyDrop.html.

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Wolfram Research (2014), KeyDrop, Wolfram Language function, https://reference.wolfram.com/language/ref/KeyDrop.html.

CMS

Wolfram Language. 2014. "KeyDrop." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/KeyDrop.html.

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Wolfram Language. 2014. "KeyDrop." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/KeyDrop.html.

APA

Wolfram Language. (2014). KeyDrop. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/KeyDrop.html

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Wolfram Language. (2014). KeyDrop. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/KeyDrop.html

BibTeX

@misc{reference.wolfram_2025_keydrop, author="Wolfram Research", title="{KeyDrop}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/KeyDrop.html}", note=[Accessed: 15-April-2025 ]}

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@misc{reference.wolfram_2025_keydrop, author="Wolfram Research", title="{KeyDrop}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/KeyDrop.html}", note=[Accessed: 15-April-2025 ]}

BibLaTeX

@online{reference.wolfram_2025_keydrop, organization={Wolfram Research}, title={KeyDrop}, year={2014}, url={https://reference.wolfram.com/language/ref/KeyDrop.html}, note=[Accessed: 15-April-2025 ]}

✖
@online{reference.wolfram_2025_keydrop, organization={Wolfram Research}, title={KeyDrop}, year={2014}, url={https://reference.wolfram.com/language/ref/KeyDrop.html}, note=[Accessed: 15-April-2025 ]}