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<h4>Lambda:</h4>
<p>Lambda helps us to write one liner function to keep python syntax short and intact. Usually we make a function in the syntax shown below:</p>
<pre class="language-python"><code>def add(a, b):
    s = a+b
    return s
print(add(4,12))</code></pre>
<p>But with the help of lambda we can make the same function like this:</p>
<pre class="language-python"><code>add = lambda x,y:x+y
print(add(4,12))</code></pre>
<p>Output of both the functions is same:</p>
<pre class="language-python"><code>16</code></pre>
<p>Let&rsquo;s understand how it works. Syntax of lambda is:</p>
<pre class="language-python"><code># lambda argument : condition/output</code></pre>
<p>We first make a variable and write lambda then arguments which in case of def(x,y) are x,y then we write the condition and that would be our output too so both. Although it's not always necessary to make a variable. Here is an example for your convenience:</p>
<pre class="language-python"><code>def x(val):
    return val[1]

a = [(1,2), (4,5), (555,3)]
a.sort(key=x)
print(a)</code></pre>
<p>&lt;|AD|&gt;</p>
<p>This is how we usually give "key" a function but we can do it like this too:</p>
<pre class="language-python"><code>a = [(1,2), (4,5), (555,3)]
a.sort(key=lambda x:x[1])
print(a)</code></pre>
<p>It is small, clean, compact and readable. Output of both is:</p>
<pre class="language-python"><code>[(1, 2), (555, 3), (4, 5)]</code></pre>
<p>In this, key value 1 which is 2, 3, 5(because count starts from 0) is checked by sort function. In case of integers it checked if key value 1 is going from small number to big, it wasn't. That's why in output 555, 3 is on second place(because 3 is smaller than 5).</p>
<h4>#tut7.py file as described in the video</h4>
<pre class="language-python"><code>'''
Syntax:
lambda argument : manipulate(argument)
'''

# def add(a, b):
#     s = a+b
#     return s
add = lambda x,y:x+y
print(add(4,12))

# def x(val):
#     return val[1]

a = [(1,2), (4,5), (555,34)]
a.sort(key= lambda x:x[1])

print(a)
</code></pre>