Truncate Python Dictionary at Given Length

To truncate a Python Dictionary at a given length, use the itertools module. This module implements a number of iterator building blocks inspired by constructs from APL, Haskell, and SML. For truncating at a given length, we will use the islice() method of the itertools module.

The module standardizes a core set of fast, memory efficient tools that are useful by themselves or in combination. Together, they form an iterator algebra making it possible to construct specialized tools succinctly and efficiently in pure Python.

Syntax

Here's the syntax ?

itertools.islice(sequence, stop)
or
itertools.islice(sequence, start, stop, step)

Above, the sequence parameter is the item you want to iterate, whereas stop is to stop the iteration at a specific position. The start is where the iteration begins. The step helps in skipping the items. The islice() does not support negative values for start, stop, or step.

Truncate a Dictionary at a given length

We will truncate a dictionary with four key:value pairs to two using the itertools module islice() method. The items are truncated to two and the same we have set as a parameter ?

Example

import itertools

# Creating a Dictionary with 4 key-value pairs
myprod = {
	"Product":"Mobile",
	"Model": "XUT",
	"Units": 120,
	"Available": "Yes"
}

# Displaying the Dictionary
print("Dictionary =\n",myprod)

# Truncating a Dictionary using the islice()
myprod = dict(itertools.islice(myprod.items(),2))

# Displaying the Dictionary
print("Dictionary after truncating =\n",myprod)

Output

Dictionary =
 {'Product': 'Mobile', 'Model': 'XUT', 'Units': 120, 'Available': 'Yes'}
Dictionary after truncating =
 {'Product': 'Mobile', 'Model': 'XUT'}

Truncate a Dictionary in a given range

We will truncate a dictionary with six key:value pairs using the itertools module islice() method. The items are truncated in a range since we have set the start and stop parameters ?

Example

import itertools

# Creating a Dictionary with 6 key-value pairs
myprod = {
	"Product":"Mobile",
	"Model": "XUT",
	"Units": 120,
	"Available": "Yes",
	"Grade": "A",
	"Rating": "5"
}

# Displaying the Dictionary
print("Dictionary =\n",myprod)

# Truncating a Dictionary using the islice()
# We have set the parameters start and stop to truncate in a range
myprod = dict(itertools.islice(myprod.items(),3,5))

# Displaying the Dictionary
print("Dictionary after truncating =\n",myprod)

Output

Dictionary =
 {'Product': 'Mobile', 'Model': 'XUT', 'Units': 120, 'Available': 'Yes', 'Grade': 'A', 'Rating': '5'}
Dictionary after truncating =
 {'Available': 'Yes', 'Grade': 'A'}

Truncate a Dictionary by skipping the items

We will truncate a dictionary with six key:value pairs using the itertools module islice() method. The items are truncated in a range since we have set the start and stop parameters. The items are skipped using the step parameter ?

Example

import itertools
# Creating a Dictionary with 6 key-value pairs
myprod = {
	"Product":"Mobile",
	"Model": "XUT",
	"Units": 120,
	"Available": "Yes",
	"Grade": "A",
	"Rating": "5"
}

# Displaying the Dictionary
print("Dictionary =\n",myprod)

# Truncating a Dictionary using the islice()
# We have set the parameters start, stop and step to skip items
myprod = dict(itertools.islice(myprod.items(),2,5,2))

# Displaying the Dictionary
print("Dictionary after truncating =\n",myprod)

Output

Dictionary =
 {'Product': 'Mobile', 'Model': 'XUT', 'Units': 120, 'Available': 'Yes', 'Grade': 'A', 'Rating': '5'}
Dictionary after truncating =
 {'Units': 120, 'Grade': 'A'}