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Python: Incorrect number of bindings supplied when EXECUTEMANY

Trying to pick up some python. I'm quite new to it at the moment.
I created the code below, but it returns an error.
I am able to get it to work when creating a second column and write multiple values to the db but a single value doesn't seem to work. Probably a list, tuple thing, but can not figure out what exactly.
Error:
Traceback (most recent call last):
File "test.py", line 15, in <module>
cursor.executemany("INSERT INTO combination VALUES (?)", combination)
sqlite3.ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 2 supplied.
Code:
import sqlite3
conn = sqlite3.connect("combinations.db")
cursor = conn.cursor()
cursor.execute(r"create table if not exists combination (string text)")
combination = []
chars = "abcd"
for char1 in chars:
for char2 in chars:
combination.append((char1+char2))
cursor.executemany("INSERT INTO combination VALUES (?)", combination)
conn.commit()

You missed making the string into a tuple when adding to the list. The argument to executemany expects a list of iterables, so if you pass it a single string 'ab' in the list, it will treat it as a 2-item iterator of a & b - hence the error.
You need to make the string 'ab' into a 1-item tuple like ('ab',). You do this by adding a trailing comma to the expression you're appending:
combination.append((char1+char2,))
Full code:
import sqlite3
conn = sqlite3.connect("combinations.db")
cursor = conn.cursor()
cursor.execute(r"create table if not exists combination (string text)")
combination = []
chars = "abcd"
for char1 in chars:
for char2 in chars:
combination.append((char1+char2,)) # ('ab',) etc.
cursor.executemany("INSERT INTO combination VALUES (?)", combination)
conn.commit()

Inserting multi-word string and an empty array with psycopg2

psycopg2 complains when inserting multiple words, empty strings, and empty arrays:
name = "Meal Rounds"
description = ""
sizes = []
cur.execute(""" INSERT INTO items (name, description, sizes) VALUES (%s, %s, %s)""" % (name, description, sizes))
Errors:
# Multi word error
psycopg2.ProgrammingError: syntax error at or near "Rounds"
LINE 1: ... (name, description, sizes) VALUES (Meal Rounds, , ...
^
# Empty string error
psycopg2.ProgrammingError: syntax error at or near ","
LINE 1: ...scription, sizes) VALUES ("Meal Rounds", , [], Fals...
^
# Empty array error
psycopg2.ProgrammingError: syntax error at or near "["
LINE 1: ...n, sizes) VALUES ("Meal Rounds", "None", [], False)...
^
I can get around the multi word error by escaping:
""" INSERT INTO items (name, description, sizes) VALUES (\"%s\", \"%s\", %s)"""
But for tables with 15+ columns, escaping each one is a pain. Does psycopg2 not handle this in an easier fashion? It will still throw errors for empty strings though.
How do I insert multiple words more efficiently, and how to insert empty strings and arrays?
Here is what psql prints out on my columns:
name | character varying(255) |
description | character varying(255) |
sizes | integer[] |

Your call to execute is creating a string with Python string substitution, which is turning out to be invalid SQL. You should be using the parameter substitution provided by the Python DB API:
https://www.python.org/dev/peps/pep-0249/#id15
To call execute using parameter substitution, you pass it two arguments. The first is the query with parameter strings which are database dependent. Psycopg2 uses "pyformat" paramstyle so your query will work as written. The second argument should be the variables you want to substitute into the query. The database driver will handle all the quoting/escaping you need. So your call to execute should be
cur.execute("""INSERT INTO items (name, description, sizes) VALUES (%s, %s, %s)""", (name, description, sizes))

Python: Iterating through MySQL columns

I'm wondering if you can help me. I'm trying to change the value in each column if the text matches a corresponding keyword. This is the loop:
for i in range(0, 20, 1):
cur.execute("UPDATE table SET %s = 1 WHERE text rlike %s") %(column_names[i], search_terms[i])
The MySQL command works fine on its own, but not when I put it in the loop. It's giving an error at the first %s
Does anyone have any insights?
This is the error:
_mysql_exceptions.ProgrammingError: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '%s = 1 WHERE text rlike %s' at line 1")
Column names looks like
column_names = ["col1","col2","col3"...]
Search terms look like
search_terms = ["'(^| |.|-)word1[;:,. ?-]'","'(^| |.|-)word2[;:,. ?-]'",...]

The right way to do this is to give values to Python, which will quote things correctly.
adapted from voyager's post:
for i in range(0, 20, 1):
cur.execute("UPDATE table SET {} = 1 WHERE text rlike %s".format(column_names[i]),
(search_terms[i],),
)
In this case it's confusing because the column_name isn't a value, it's part of the table structure, so it's inserted using good old string formatting. The search_term is a value, so is passed to cursor.execute() for correct, safe quoting.
(Don't use string manipulation to add the quotes -- you're exposing yourself to SQL injection.)

Missing quotes and wrong parenthesis placement...
for i in range(0, 20, 1):
cur.execute("UPDATE table SET %s = 1 WHERE text rlike '%s'" %(column_names[i], search_terms[i]))
# ^ ^
# (-----------------------------------------------------------------------------------)
Please note, this is not the right way of doing this, if your string may contain quotes by itself...
What about that instead:
for i in range(0, 20, 1):
cur.execute("UPDATE table SET %s = 1 WHERE text rlike ?" % (column_names[i],),
(search_terms[i],))
This uses the % operator to set the column name, but uses an executes parameter to bind the data, letting the DB driver escape all characters that need so.

Python database insert

I've been trying to parse a text file (opened with parameter encoding='utf8') and insert extracted values into an mdb database using pyodbc module.
I have tried the code below:
for line in fp:
tokens = line.split('\t')
tokens[4] = tokens[4][:len(tokens[4])-1] #to avoid the \n
tokens[1] = tokens[1][1:] #to remove the 'u' from the beginning of utf8 characters like u'\u0622'
content = conn.execute("INSERT INTO Entries (PForm, WForm, Code, Freq, Pattern) VALUES ("+tokens[0]+","+tokens[1]+","+tokens[2]+","+tokens[3]+","+tokens[4]+")")
conn.commit()
and received the following error:
Error: ('07002', '[07002] [Microsoft][ODBC Microsoft Access Driver] Too few parameters. Expected 4. (-3010) (SQLExecDirectW)')
P.S. the first line of my file is: آ 'A Ab 1 S
And the other lines are of the same format.
Your comments will be appreciated :)

You don't put quotes around the strings which you want to insert. Assuming the "Freq" row is of type INTEGER:
stmt = """
INSERT INTO Entries (PForm, WForm, Code, Freq, Pattern)
VALUES ('%s', '%s', '%s', %s, '%s')
"""
params = tuple(t for t in tokens)
conn.execute(stmt % params)
But anyway, you shouldn't be formatting an INSERT statement like this. Doesn't the library you're using provide a facility to parameterize statements ? Something like this:
conn.execute("INSERT INTO Foo VALUES (?, ?, ?)", (foo, bar, baz))

IndexError string index out of range when referencing first character

Here is my code (currently):
conn = sqlite3.connect(db)
conn.text_factory = str #bugger 8-bit bytestrings
cur = conn.cursor()
reader = csv.reader(open(csvfile, "rU"), delimiter = '\t')
for Number, Name, Message, Datetime, Type in reader:
# populate subscriber table
if str(Number)[0] == '1': # errors on this line
tmpNumber = str(Number)[1:]
Number = int(tmpNumber)
cur.execute('INSERT OR IGNORE INTO subscriber (name, phone_number) VALUES (?,?)', (Name, Number))
cur.close()
conn.close()
It returns this error on the line commented to indicate where the error lies:
IndexError: string index out of range
All of the numbers have values, but if the phone number starts with a 1 I want to remove the 1 before inserting it into the database. Why won't this work? I've converted it to a string before trying to reference the first character, so I don't understand why this isn't working.

Seems like you are getting an empty string. Try replacing your if statement with the following and see if it works.
if str(Number).startswith('1'):
(Edited to reflect #kindall 's suggestion of using startswith instead of slicing [:1]).