Basic Python Functions and Methods (v. 2.7.10)
Basic Built-in Functions
raw_input() |
Reads a line from input, converts it to a string and returns that |
len() |
Returns the length (the number of items) of an object |
max() |
Returns the largest item in the list or the largest of the two or more arguments |
min() |
Returns the smallest item in the list or the smallest of the two or more arguments |
pow() |
Returns first argument to the power second argument |
range(start, stop, step) |
Returns a list of integers starting from start and ending at stop (exclusive), having a difference of step between any two adjacent elements |
xrange() |
Similar to range(), but returns an xrange iterator object instead of a list |
bin() |
Converts an integer number to a binary string |
oct() |
Converts an integer number to an octal string |
hex() |
Converts an integer nuber to a lowercase hexadecimal string prefixed with ‘0x’ |
int() |
Returns an integer object from a number or string |
float() |
Returns a floating point number from a number or string |
type() |
Returns the type of any object |
File Methods and Constants
open() | Opens a file, returning an object of the file type |
close() | Closes the file; a closed file cannot be read or written any more |
flush() | Flushes the internal buffer |
fileno() | Returns the integer “file descriptor” that is used by the underlying implementation to request I/O operations from the operating system |
tell() | Returns the file’s current position |
truncate() | Truncates the file’s size |
write() | Writes a string to the file |
writelines() | Writes a sequence of strings to the file |
closed | Bool indicating the current state of the file object |
encoding | The encoding that this file uses |
errors | The Unicode error handler used along with the encoding |
mode | The I/O mode for the file |
name | The name of the file |
String Methods
str() |
Create a new empty string |
upper() |
Returns a string in all uppercase |
lower() |
Returns a string in all lowercase |
capitalize() |
Returns a string with first character capitalized, the rest lower |
strip() |
Returns a string with the leading and trailing whitespace removed |
lstrip() |
Returns a string with the leading whitespace removed |
rstrip() |
Returns a string with the trailing whitespace removed |
count() |
Returns the number of occurrences of item |
replace() |
Replaces all occurrences of old substring with new |
center() |
Returns a string centered in a field of width spaces |
ljust() |
Returns a string left justified in a field of width spaces |
rjust() |
Returns a string right justified in a field of width spaces |
find() |
Returns the leftmost index where the substring item is found |
rfind() |
Returns the rightmost index where the substring item is found |
index() |
Similar to find() except causes a runtime error if item is not found |
rindex() |
Similar to rfind() except causes a runtime error if item is not found |
chr() |
Returns a string of one character whose ASCII code is the integer passed as argument |
ord() |
Returns an integer representing the Unicode code point of any string of one character |
Math Functions and Constants
abs() Returns the absolute value of a number factorial() Returns factorial of the argument value round() Returns the floating point value number to the given number of digits after the decimal point exp() Returns the argument raised to a power (e**x) log() Returns logarithm of argument value pow() Returns first parameter raised to the power by second parameter sqrt() Takes squareroot of argument value pi The mathematical constant π = 3.141592… e The mathematical constant e = 2.718281
List (Array) Methods
list() | Creates a new empty list |
append() | Adds an item to the end of the list |
extend() | Extends the list by appending all the items in the given list |
insert() | Inserts an item at a given position |
remove() | Removes the first item from the list with aforementioned parameter value |
pop() | Removes the item at the given position in the list, and return it |
index() | Returns the index in the list |
count() | Returns the number of times that appears in the list. |
sort() | Sorts the items of the list in place |
sort(reverse=True) | Sorts the items of the list in place, in descending order |
reverse() | Reverses the elements of the list, in place |
sum() | Returns the total sum of all items of the list |
join() | Concatenates all the items of the list |
Dictionary Methods
dict() | Creates a new empty dictionary |
keys() | Returns list of dictionary keys |
values() | Returns list of dictionary values |
clear() | Removes all elements of dictionary |
copy() | Returns a shallow copy of dictionary |
Date and Time Methods
replace() | Gives new values by whichever keyword arguments are specified |
toordinal() | Returns the proleptic Gregorian ordinal of the date, where January 1 of year 1 has ordinal 1 |
weekday() | Returns the day of the week as an integer, where Monday is 0 and Sunday is 6 |
isoweekday() | Returns the day of the week as an integer, where Monday is 1 and Sunday is 7 |
isocalendar() | Returns a 3-tuple, (ISO year, ISO week number, ISO weekday) |
isoformat() | Returns a string representing the date in ISO 8601 format, “YYYY-MM-DD” |
__str__() | For a date d, str(d) is equivalent to d.isoformat() |
ctime() | Returns a string representing the date |
strftime() | Returns a string representing the date, controlled by an explicit format string |
__format__() | Same as date.strftime(). This makes it possible to specify format string for a date object when using str.format() |