﻿ Python: Find the maximum profit in one transaction - w3resource

# Python: Find the maximum profit in one transaction

## Python Basic - 1: Exercise-77 with Solution

The price of a given stock on each day is stored in an array.
Write a Python program to find the maximum profit in one transaction i.e., buy one and sell one share of the stock from the given price value of the said array. You cannot sell a stock before you buy one.
Input (Stock price of each day): [224, 236, 247, 258, 259, 225]
Output: 35
Explanation:
236 - 224 = 12
247 - 224 = 23
258 - 224 = 34
259 - 224 = 35
225 - 224 = 1
247 - 236 = 11
258 - 236 = 22
259 - 236 = 23
225 - 236 = -11
258 - 247 = 11
259 - 247 = 12
225 - 247 = -22
259 - 258 = 1
225 - 258 = -33
225 - 259 = -34

Sample Solution:

Python Code:

``````def max_profit(stock_price):
max_profit_amt = 0

for i in range(len(stock_price)):
profit_amt = 0
for j in range(i+1, len(stock_price)):
profit_amt = stock_price[j] - stock_price[i]
if  profit_amt > max_profit_amt:
max_profit_amt = profit_amt
return max_profit_amt
print(max_profit([224, 236, 247, 258, 259, 225]))
``````

Sample Output:

```35
```

Flowchart:

Python Code Editor:

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## Python: Tips of the Day

Iterating over dictionaries using 'for' loops:

I am a bit puzzled by the following code: d = {'x': 1, 'y': 2, 'z': 3} for key in d: print key, 'corresponds to', d[key] What I don't understand is the key portion. How does Python recognize ...

key is just a variable name.

```for key in d:
```

For Python 3.x:

```for key, value in d.items():
```

For Python 2.x:

```for key, value in d.iteritems():
```

To test for yourself, change the word key to poop.

In Python 3.x, iteritems() was replaced with simply items(), which returns a set-like view backed by the dict, like iteritems() but even better. This is also available in 2.7 as viewitems().

The operation items() will work for both 2 and 3, but in 2 it will return a list of the dictionary's (key, value) pairs, which will not reflect changes to the dict that happen after the items() call. If you want the 2.x behavior in 3.x, you can call list(d.items()).

Ref: https://bit.ly/37dm0Qo