this is a python script to see wifi around you with percentage of signal strength and info about you wifi card works on windows only
for linux you my use iwlist wlan0 scanning

from ctypes import *
from ctypes.wintypes import *
from sys import exit

def customresize(array, new_size):
return (array._type_*new_size).from_address(addressof(array))

wlanapi = windll.LoadLibrary('wlanapi.dll')

ERROR_SUCCESS = 0

class GUID(Structure):
_fields_ = [
('Data1', c_ulong),
('Data2', c_ushort),
('Data3', c_ushort),
('Data4', c_ubyte*8),
]

WLAN_INTERFACE_STATE = c_uint
(wlan_interface_state_not_ready,
wlan_interface_state_connected,
wlan_interface_state_ad_hoc_network_formed,
wlan_interface_state_disconnecting,
wlan_interface_state_disconnected,
wlan_interface_state_associating,
wlan_interface_state_discovering,
wlan_interface_state_authenticating) = map(WLAN_INTERFACE_STATE, xrange(0, 8))

class WLAN_INTERFACE_INFO(Structure):
_fields_ = [
("InterfaceGuid", GUID),
("strInterfaceDescription", c_wchar * 256),
("isState", WLAN_INTERFACE_STATE)
]

class WLAN_INTERFACE_INFO_LIST(Structure):
_fields_ = [
("NumberOfItems", DWORD),
("Index", DWORD),
("InterfaceInfo", WLAN_INTERFACE_INFO * 1)
]

WLAN_MAX_PHY_TYPE_NUMBER = 0x8
DOT11_SSID_MAX_LENGTH = 32
WLAN_REASON_CODE = DWORD
DOT11_BSS_TYPE = c_uint
(dot11_BSS_type_infrastructure,
dot11_BSS_type_independent,
dot11_BSS_type_any) = map(DOT11_BSS_TYPE, xrange(1, 4))
DOT11_PHY_TYPE = c_uint
dot11_phy_type_unknown = 0
dot11_phy_type_any = 0
dot11_phy_type_fhss = 1
dot11_phy_type_dsss = 2
dot11_phy_type_irbaseband = 3
dot11_phy_type_ofdm = 4
dot11_phy_type_hrdsss = 5
dot11_phy_type_erp = 6
dot11_phy_type_ht = 7
dot11_phy_type_IHV_start = 0x80000000
dot11_phy_type_IHV_end = 0xffffffff

DOT11_AUTH_ALGORITHM = c_uint
DOT11_AUTH_ALGO_80211_OPEN = 1
DOT11_AUTH_ALGO_80211_SHARED_KEY = 2
DOT11_AUTH_ALGO_WPA = 3
DOT11_AUTH_ALGO_WPA_PSK = 4
DOT11_AUTH_ALGO_WPA_NONE = 5
DOT11_AUTH_ALGO_RSNA = 6
DOT11_AUTH_ALGO_RSNA_PSK = 7
DOT11_AUTH_ALGO_IHV_START = 0x80000000
DOT11_AUTH_ALGO_IHV_END = 0xffffffff

DOT11_CIPHER_ALGORITHM = c_uint
DOT11_CIPHER_ALGO_NONE = 0x00
DOT11_CIPHER_ALGO_WEP40 = 0x01
DOT11_CIPHER_ALGO_TKIP = 0x02
DOT11_CIPHER_ALGO_CCMP = 0x04
DOT11_CIPHER_ALGO_WEP104 = 0x05
DOT11_CIPHER_ALGO_WPA_USE_GROUP = 0x100
DOT11_CIPHER_ALGO_RSN_USE_GROUP = 0x100
DOT11_CIPHER_ALGO_WEP = 0x101
DOT11_CIPHER_ALGO_IHV_START = 0x80000000
DOT11_CIPHER_ALGO_IHV_END = 0xffffffff

WLAN_AVAILABLE_NETWORK_CONNECTED = 1
WLAN_AVAILABLE_NETWORK_HAS_PROFILE = 2

WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_ADHOC_PROFILES = 0x00000001
WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_MANUAL_HIDDEN_PROFILES = 0x00000002

class DOT11_SSID(Structure):
_fields_ = [
("SSIDLength", c_ulong),
("SSID", c_char * DOT11_SSID_MAX_LENGTH)
]

class WLAN_AVAILABLE_NETWORK(Structure):
_fields_ = [
("ProfileName", c_wchar * 256),
("dot11Ssid", DOT11_SSID),
("dot11BssType", DOT11_BSS_TYPE),
("NumberOfBssids", c_ulong),
("NetworkConnectable", c_bool),
("wlanNotConnectableReason", WLAN_REASON_CODE),
("NumberOfPhyTypes", c_ulong),
("dot11PhyTypes", DOT11_PHY_TYPE * WLAN_MAX_PHY_TYPE_NUMBER),
("MorePhyTypes", c_bool),
("wlanSignalQuality", c_ulong),
("SecurityEnabled", c_bool),
("dot11DefaultAuthAlgorithm", DOT11_AUTH_ALGORITHM),
("dot11DefaultCipherAlgorithm", DOT11_CIPHER_ALGORITHM),
("Flags", DWORD),
("Reserved", DWORD)
]

class WLAN_AVAILABLE_NETWORK_LIST(Structure):
_fields_ = [
("NumberOfItems", DWORD),
("Index", DWORD),
("Network", WLAN_AVAILABLE_NETWORK * 1)
]

WlanOpenHandle = wlanapi.WlanOpenHandle
WlanOpenHandle.argtypes = (DWORD, c_void_p, POINTER(DWORD), POINTER(HANDLE))
WlanOpenHandle.restype = DWORD

WlanEnumInterfaces = wlanapi.WlanEnumInterfaces
WlanEnumInterfaces.argtypes = (HANDLE, c_void_p,
POINTER(POINTER(WLAN_INTERFACE_INFO_LIST)))
WlanEnumInterfaces.restype = DWORD

WlanGetAvailableNetworkList = wlanapi.WlanGetAvailableNetworkList
WlanGetAvailableNetworkList.argtypes = (HANDLE, POINTER(GUID), DWORD, c_void_p,
POINTER(POINTER(WLAN_AVAILABLE_NETWORK_LIST)))
WlanGetAvailableNetworkList.restype = DWORD

WlanFreeMemory = wlanapi.WlanFreeMemory
WlanFreeMemory.argtypes = [c_void_p]

if __name__ == '__main__':
NegotiatedVersion = DWORD()
ClientHandle = HANDLE()
ret = WlanOpenHandle(1, None, byref(NegotiatedVersion), byref(ClientHandle))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
# find all wireless network interfaces
pInterfaceList = pointer(WLAN_INTERFACE_INFO_LIST())
ret = WlanEnumInterfaces(ClientHandle, None, byref(pInterfaceList))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
try:
ifaces = customresize(pInterfaceList.contents.InterfaceInfo,
pInterfaceList.contents.NumberOfItems)
# find each available network for each interface
for iface in ifaces:
print "Interface: %s" % (iface.strInterfaceDescription)
pAvailableNetworkList = pointer(WLAN_AVAILABLE_NETWORK_LIST())
ret = WlanGetAvailableNetworkList(ClientHandle,
byref(iface.InterfaceGuid),
0,
None,
byref(pAvailableNetworkList))
if ret != ERROR_SUCCESS:
exit(FormatError(ret))
try:
avail_net_list = pAvailableNetworkList.contents
networks = customresize(avail_net_list.Network,
avail_net_list.NumberOfItems)
for network in networks:
print "SSID: %s, quality: %02d%%" % (
network.dot11Ssid.SSID[:network.dot11Ssid.SSIDLength],
network.wlanSignalQuality)
finally:
WlanFreeMemory(pAvailableNetworkList)
finally:
WlanFreeMemory(pInterfaceList)