Difference between revisions of "Python"
From ScienceZero
(→Bitwise functions) |
(→Writing to a text file) |
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==Writing to a text file== | ==Writing to a text file== | ||
with open("filename.txt", "w") as outputfile1: #w for write, change to a for append to add to the bottom of an existing file | with open("filename.txt", "w") as outputfile1: #w for write, change to a for append to add to the bottom of an existing file | ||
− | + | outputfile1.write("Hello\r\n") | |
outputfile1.close() | outputfile1.close() | ||
+ | |||
+ | =Strings= | ||
+ | ==Combining strings== | ||
+ | print "abc" + "123" | ||
[[Category:Computing]] | [[Category:Computing]] |
Revision as of 12:09, 2 October 2017
Application
File Header
#!/usr/bin/python
Comments
These begin with the # character
Libraries
Subroutines
These must be placed at the top, under the file header and library includes
def functionname(value): #do something return somevariable
Variables
There is no method to define a variable type, it is determined by the type of the first value it gets set to
a = 42 will create an int called a with value 42
Loops
Infinite
while True: #code to loop
While (check then run)
a = 0 while a < 10: a += 1
While (run then check)
while True: #code if i == 10: break #this exits the while loop
For
for i in range(127,-1,-1): #step from 127 to 0 by 1 print i
Conditionals
Equal
if i == 10: print i
Not equal
if i != 10: print i
Greater than
if i > 10: print i
Less than
if i < 10: print i
Greater than or equal to
if i >= 10: print i
Less than or equal to
if i <= 10: print i
If Else
if i == 10: print i else: print "I isn't 10"
Math
a = b + 2 #addition a = b - 2 #subtraction a = b * 2 #multiplication a = b / 2 #division a = b % 2 #modulo division (divides b by 2, and returns the remainder)
Bitwise functions
a = b >> 2 #shift the bits of an int right by an amount of times (2 in this case) a = b << 2 #shift the bits of an int left by an amount of times (2 in this case) a = b | 2 #sets a to all the bits in b logical ORed with all the bits in 2 a = b & 2 #sets a to all the bits in b logical ANDed with all the bits in 2 a = a ^ 2 #sets a to all the bits in b logical XORed with all the bits in 2 a = ~ b #sets a to all the bits in b switched (0s become 1, 1s become 0)
Files
Writing to a text file
with open("filename.txt", "w") as outputfile1: #w for write, change to a for append to add to the bottom of an existing file outputfile1.write("Hello\r\n") outputfile1.close()
Strings
Combining strings
print "abc" + "123"