Python 3.x3.0
In Python 3, print functionality is in the form of a function:
print("This string will be displayed in the output")
# This string will be displayed in the output
print("You can print \n escape characters too.")
# You can print escape characters too.
Pyth...
def input_number(msg, err_msg=None):
while True:
try:
return float(raw_input(msg))
except ValueError:
if err_msg is not None:
print(err_msg)
def input_number(msg, err_msg=None):
while True:
try:
return ...
Python 2.x2.3
In Python 2.x, to continue a line with print, end the print statement with a comma. It will automatically add a space.
print "Hello,",
print "World!"
# Hello, World!
Python 3.x3.0
In Python 3.x, the print function has an optional end parameter that is what...
In the event that geolocation fails, your callback function will receive a PositionError object. The object will include an attribute named code that will have a value of 1, 2, or 3. Each of these numbers signifies a different kind of error; the getErrorCode() function below takes the PositionError....
with open(input_file, 'r') as in_file, open(output_file, 'w') as out_file:
for line in in_file:
out_file.write(line)
Using the shutil module:
import shutil
shutil.copyfile(src, dst)
This a Basic example for using the MVVM model in a windows desktop application, using WPF and C#. The example code implements a simple "user info" dialog.
The View
The XAML
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
...
You can upvote (or downvote, if you want...) examples you created.
Although you won't get any reputation for doing so, upvoting your the example will influence the examples' ordering on the page.
Any previous contributors to the examples will get reputation.
On the other hand, you might consider ...
Python's string type provides many functions that act on the capitalization of a string. These include :
str.casefold
str.upper
str.lower
str.capitalize
str.title
str.swapcase
With unicode strings (the default in Python 3), these operations are not 1:1 mappings or reversible. Most of thes...
str.split(sep=None, maxsplit=-1)
str.split takes a string and returns a list of substrings of the original string. The behavior differs depending on whether the sep argument is provided or omitted.
If sep isn't provided, or is None, then the splitting takes place wherever there is whitespace. Howe...
Python's str type also has a method for replacing occurences of one sub-string with another sub-string in a given string. For more demanding cases, one can use re.sub.
str.replace(old, new[, count]):
str.replace takes two arguments old and new containing the old sub-string which is to be replace...
In the following example - Database for an auto shop business, we have a list of departments, employees, customers and customer cars. We are using foreign keys to create relationships between the various tables.
Live example: SQL fiddle
Relationships between tables
Each Department may have 0 ...
Since PHP 5.0, PDO has been available as a database access layer. It is database agnostic, and so the following connection example code should work for any of its supported databases simply by changing the DSN.
// First, create the database handle
//Using MySQL (connection via local socket):
$d...
The json module contains functions for both reading and writing to and from unicode strings, and reading and writing to and from files. These are differentiated by a trailing s in the function name. In these examples we use a StringIO object, but the same functions would apply for any file-like obje...
A quick way to make a copy of an array (as opposed to assigning a variable with another reference to the original array) is:
arr[:]
Let's examine the syntax. [:] means that start, end, and slice are all omitted. They default to 0, len(arr), and 1, respectively, meaning that subarray that we are ...
It's possible to create generator iterators using a comprehension-like syntax.
generator = (i * 2 for i in range(3))
next(generator) # 0
next(generator) # 2
next(generator) # 4
next(generator) # raises StopIteration
If a function doesn't necessarily need to be passed a list, you can sa...
a, b = 2, 3
a * b # = 6
import operator
operator.mul(a, b) # = 6
Possible combinations (builtin types):
int and int (gives an int)
int and float (gives a float)
int and complex (gives a complex)
float and float (gives a float)
float and complex (gives a comple...
a, b = 2, 3
(a ** b) # = 8
pow(a, b) # = 8
import math
math.pow(a, b) # = 8.0 (always float; does not allow complex results)
import operator
operator.pow(a, b) # = 8
Another difference between the built-in pow and math.pow is that the built-in po...
