Some Basic Knowledge Points of Python Programming

if __name__ == "__main__"：# do sth.

This tells Python that you only what to run the following code if this program is executed as a standalone file. We can use it to test our code.

When you do import a module, it will NOT run the code that is under the conditional because

__name__

will no longer equal

"__main__"

.

dict.keys()

In Python 2.x, the

keys()

method returns a list. In Python 3.x, it returns a view object.

"name" in my_dict # this is good
"name" in my_dict.keys() # this works too, but is slower

String Formatting

'''
old ways
'''
"I like %s" % "python"
"I like %s and %s" % ("python", "c++")

'''
Templates and the New String Formatting Methodlogy
'''

"%(lang)s is fun!" % {lang : "Python", key : value, ...}

"Python is as simple as {0} and {1}".format( "MATLAB", "R" )

xy = { "x" : 0, "y" : 1 }
"Graph a ponit at where x={x} and y={y}".format(**xy)